'Dar He Blogs!

Random Links: Read "Short White Coat," the Value of a Good Kindergarten Experience, and Why Drop Out?

2012-01-29T18:54:00.003-05:00

My co-intern in the primary care program, Ishani Ganguli, is an incredibly thoughtful individual who writes really well. She has a blog (a real blog, one with a consistently large readership that is fronted by the Boston Globe) that discusses various aspects of health care and medical education through the eyes of a resident. Worth checking out, especially her latest post on teamwork in health care.

-There's a great book, now a classic, by Robert Fulgham called "All I Really Need to Know I Learned in Kindergarten." Now some new research from some big shot economists on the value of a good kindergarten experience:

In Project STAR, 11,571 students in Tennessee and their teachers were randomly assigned to classrooms within their schools from kindergarten to third grade. This paper evaluates the long-term impacts of STAR by linking the experimental data to administrative records. We first demonstrate that kindergarten test scores are highly correlated with outcomes such as earnings at age 27, college attendance, home ownership, and retirement savings. We then document four sets of experimental impacts. First, students in small classes are significantly more likely to attend college and exhibit improvements on other outcomes. Class size does not have a significant effect on earnings at age 27, but this effect is imprecisely estimated. Second, students who had a more experienced teacher in kindergarten have higher earnings. Third, an analysis of variance reveals significant classroom effects on earnings. Students who were randomly assigned to higher quality classrooms in grades K-3 – as measured by classmates' end-of-class test scores – have higher earnings, college attendance rates, and other outcomes. Finally, the effects of class quality fade out on test scores in later grades but gains in non-cognitive measures persist.

-In related news, there's a great recent NYT Op-Ed on the cost of high school dropouts to the US economy (thanks James Hudspeth!). The authors (both well known economists) mention the following:

Studies show that the typical high school graduate will obtain higher employment and earnings — an astonishing 50 percent to 100 percent increase in lifetime income — and will be less likely to draw on public money for health care and welfare and less likely to be involved in the criminal justice system.

So a good economics question: if high school completion is so valuable, why would anyone drop out? Is it because of ability (low ability kids are forced out), time preference (the value of now exceeds the returns of income later?), or a lack of information about the returns to high school? There are other explanations. But if we assume that people make choices based on marginal returns, it seems bizarre that so many would drop out and leave that kind of money on the table, right? Thoughts?

Partisan Professors and Race

2012-01-27T18:49:00.002-05:00

Great new paper in the latest issue of the American Economic Journal: Applied Economics about the political orientation of your professor and the grade you may receive in her/his class:

We study grading outcomes associated with professors in an elite university in the United States who were identified—using voter registration records from the county where the university is located—as either Republicans or Democrats. The evidence suggests that student grades are linked to the political orientation of professors. Relative to their Democratic colleagues, Republican professors are associated with a less egalitarian distribution of grades and with lower grades awarded to black students relative to whites.

The paper is by Bar and Zussman and their models look at variations in grades within the same student taking courses in the same department, so it controls for selection into majors and, to some extent, classes. The most interesting part of this paper is the race angle. One may think that it has something to do with the fact the demographics of Republican professors, not so much their ideological preferences. Not so: even controlling for gender, age and race of the professor doesn't change the results.

So how to interpret this? I'm sure that many would argue that Republican professors harbor some subtle, perhaps subconscious, prejudices against black students (this guy would agree). This is entirely possible, but I think the study needs to be interpreted with some caution. First, the sample size of Republican professors is small (only 5.3% are). Secondly, its unclear where the grade variation is coming from. Do students - black or white - perform worse in Republican-professor taught classes (they don't like the take on the material, they may be too ticked off with partisan politics to focus on assignments, etc)? The study can't distinguish this explanation from the racist-professor one.

Health Expenditures in the US: Are We Not Spending Enough?

2011-12-14T23:06:00.001-05:00

According the Elizabeth Bradley, a Professor of Health Policy and Administration at Yale, the answer is no. As she and Lauren Taylor point out in a recent New York Times editorial:

We studied 10 years’ worth of data and found that if you counted the combined investment in health care and social services, the United States no longer spent the most money — far from it. In 2005, for example, the United States devoted only 29 percent of gross domestic product to health and social services combined, while countries like Sweden, France, the Netherlands, Belgium and Denmark dedicated 33 percent to 38 percent of their G.D.P. to the combination. We came in 10th.

Bradley and Taylor put forth the argument that the things that make people healthy go beyond what we typically think of as health care. That is, access to employment, good housing, food security, and educational institutions all contribute to population health. I don't think this is a revolutionary thought.

But what is revolutionary is that they authors imply that the answer to our central question for US health care - "Do we get what we pay for?" - might not be the "no" we've always assumed, but a "yes." We just aren't spending enough, at least not on the proximal things that really matter. I don't think that it is that simple - it's hard to know what portion of social service spending actually improves health. But the discourse does need to move in this direction.

Furthermore, another neat aspect of this piece is that Bradley and Taylor's contention doesn't just apply to the macro-level health policy sphere. Imagine a primary care system that takes into account the socioeconomic realities of patients and creates interventions that use these insights to better provide care. A developing country example: subsidizing the transportation fees for HIV/AIDS patients who would otherwise find this to be a barrier and be unable to seek much needed health care. This sort of intervention may be equally important to any medications or lab tests in advancing the health of these patients. I'll talk more about this sort of "economic hotspotting" in a later post.

Great Harvard Med Class Show Parody

2011-12-06T14:52:00.001-05:00

As an intern, I get to work side by side with Harvard medical students. I have to say that they have all been very, very good in terms of their clinical knowledge and ability to efficiently get things done. No wonder I got rejected when I applied.

It turns out that Harvard med students are pretty funny, too. Check out this great parody of medical students' experiences while on their third year clinical rotations by members of the Class of 2014. I'm sure you'll recognize the Saturday Night Live short this is based on. (HT: the awesome and hilarious Camila Fabersunne).

Male Circumcision, HIV/AIDS and the "Real World"

2011-12-04T16:57:00.001-05:00

This past week, PLoS Medicine put forth multi-piece expose (start with this lead/summary article) on medical male circumcision, its cost-effectiveness in combating HIV/AIDS and methods and challenges to scaling up this practice in Sub-Saharan Africa, where the epidemic is at its worst. The upshot of this series of papers was covered in a recent Scientific American piece (which quotes yours truly). To summarize, the argument is that medical male circumcision works (as demonstrated in three large randomized clinical trials, all conducted in Africa) and is cost-effective. Indeed, it may even be cost-saving, with high upfront costs that are easily recovered over a 10 year period. Challenges to scale-up include finding health care workers to carry out circumcisions (in a way that doesn't crowd-out provision of other important health care services), getting people to adopt the practice in a respectful, non-coercive yet effective way, especially in areas where there are strong traditional norms over circumcision, and dealing with any risk compensating behavior (if circumcised individuals think circumcision is protective, they may be more likely to engage in riskier sexual behaviors than they otherwise would - more on this in a later post).

Circumcision is one of those topics that seems to always bring with it a vociferous debate. Those opposed to the practice make their stance known quite vehemently. In my opinion, much of what is being spouted against medical male circumcision as a tool for HIV prevention is based on an incomplete understanding of the available evidence and already strong negative priors against the practice that are almost impossible to shift (for example, see this clip or refer to any of the comments to the aforementioned Scientific American article).

However, I think there is one oft-cited argument against medical male circumcision that is worth discussing further. In particular, opponents point to evidence from a 2009 UNAIDS study that uses recent survey data from 18 African countries and concludes that "there appears no clear pattern of association between male circumcision and HIV prevalence—in 8 of 18 countries with data, HIV prevalence is lower among circumcised men, while in the remaining 10 countries it is higher." This is contrast to the large randomized clinical trials mentioned above which show that circumcision reduces HIV rates by greater than 50%. The fact that the clinical trial results are not borne out in the sample survey data, opponents argue, means that circumcision does not work in "real world settings."

In a recent study, Brendan Maughan-Brown, Nicoli Nattrass, Jeremy Seekings, Alan Whiteside and I offer a different explanation for this differential set of findings. It has to do with the fact that the UNAIDS study looks at population that were circumcised in a multitude of settings (clinics, traditional healers) whereas the clinical trials focus on medical circumcision only. In practice, there great deal of heterogeneity in traditionally circumcising populations: some people do not have all of their foreskin removed, and others are circumcised several years after their peers. In our study population of blacks living in the Cape Town metro area, when we don't account for this heterogeneity, we find only a weak negative effect of circumcision on HIV positivity. However, once we "unpack" circumcision, we find that the practice actually has a strong negative association with the probability of testing HIV positive, provided it is done earlier and that there is complete removal of the foreskin.

These results suggest that the UNAIDS results may simply be due to measurement error. In a traditional setting, a circumcision is not a circumcision is not a circumcision. Treating every circumcised person the same introduces measurement error, and statistically it is well known that this would deflate the estimates of the impacts of the practice towards zero. So, the differential results between the UNAIDS findings and the randomized clinical trial findings is not that circumcision doesn't work in the real world. Rather, it is that we really need to understand better the heterogeneity in male circumcision and what can be done to ensure better outcomes for everyone involved.

Do Financial Incentives Induce Physicians to Provide More (Unnecessary) Care?

2011-11-27T20:13:00.001-05:00

About two years ago, I posted something on my now non-existent Facebook account about how medical tests and treatments, especially those that are elective, are more likely to be offered if doctors are reimbursed well for them. My point was that there was a strong financial incentive to test and treat, even in cases where doing so would confer only little benefit to the patient's health, at best. A bunch of people (mainly physicians) responded on my wall pointing out how misguided I was. It was actually a bit more vociferous than this, but I digress.

Anyway, it turns out that I was right (in this case, NOT shocking). I just came across a great study by Joshua Gottleib, an economics job market candidate from Harvard. His study uses a natural experiment in physician incentives to examine whether payment drives care offered. Specifically, he takes advantage of a large scale policy change by Medicare in 1997. Previously, Medicare created different fee schedules for each of around 300 small geographic areas. This was done because production costs and other realities of providing a given service obviously varied across space. In 1997, they decided to coalesce these regions into 80 larger areas. For some smaller areas, there may have been large payouts for certain services which fell after 1997 because the average payout for their new larger group was lower. For others, it went the other way. In any case, comparing pre and post 1997 gives you a nice experiment as to what would happen to health services provision when payouts are changed for reasons other than local health outcomes or demand for care.

Whether you hold my priors or shared those of my misguided Facebook friends, the results remain astounding. Across all health services, Gottleib finds that "on average, a 2 percent increase in payment rates leads to a 5 percent increase in care provision per patient." Predictably the price response of services with an elective component (such as cataract surgery, colonoscopy and cardiac procedures - don't huff and puff, I said elective COMPONENT!) but not so much for things like dialysis or cancer care, where it is easy to identify who needs it and you need to do it no matter what. Furthermore, in addition to disproportionally adjusting the provision of relative intensive and elective treatments as reimbursements rise, physicians also invest in new technology to do so; this is beautifully illustrated by the examination of reimbursement rates and MRI purchases.

So what's the upshot of all this? Is this a good thing? Probably not. Despite scaling up technology, Gottleib is unable to find any impacts on health outcomes or mortality among cardiac patients (for which he explored more deeply the relationship between payouts and treatment). Furthermore, he asserts that "that changes in physician pro fit margins can explain up to one third of the growth in health spending over recent decades."

Ultimately, some good lessons here. First, if we are interested in bring down costs and increasing health care efficiency, we need to pay for things that actually help maintain and increase health. Second, we can't rely on physicians do be the gatekeepers of rising costs as it is clear that, given incentives, they may not always behave in a way that actually improves health outcomes (thankfully, for cases like fractures, cancer or end-stage renal disease treatment, docs aren't sensitive to prices and do the right thing clinically). Finally, we need to stop universally and blindly lauding the US health care system as a bastion of health care technology if that technology does little to improve outcomes.

Infections and IQ

2011-11-05T18:45:00.001-04:00

A well known fact about our world is that there are great disparities in average IQ scores across countries. In the past, some have tried to argue that this pattern be explained by innate differences in cognition across populations - some people are just innately smarter than others. Others have tried to attribute these to cultural factors. However, genetics and culture are likely not driving these differences in any meaningful sense. After all, another stylized fact is that average IQ scores have been going up markedly, within one or two generations, within any given country. These changes, also known as the Flynn Effect after the researcher who painstakingly documented them, speak against the genes story because they occurred far more quickly than one would expect from population-wide changes in the distribution of cognition-determining genes. The have occured too quickly to be explained by paradigm shifting social changes, as well.

So what gives? Enter Chris Eppig, a researcher at the University of New Mexico. In a recent piece in The Scientific American , he proposes that cross-country differences in IQ, as well as changes in IQ rates within a country over time, can be explained by exposure to infectious diseases early in life. The story goes something like this: infections early in life require energy to fight off. Energy during this age is primarily used for brain development (in infancy, it is thought that over 80% of calories are allocated to neurologic development). So if energy is diverted to fend off infections, it can't be used to develop cognitive endowments, and afflicted infants and children end up becoming adults that do poorly on IQ tests.

In the piece, Eppig cites some of his work linking infectious disease death rates in countries to average IQ scores. His models control for country income and a few other important macroeconomic variables. His evidence, while not proof of a causal relationship, is certainly provocative. So provocative in fact that I ended up trying to build a stronger causal story between early childhood infections and later life cognitive outcomes. In a recent paper (cited in the above Scientific American article), I examine the impact of early life exposure to malaria on later life performance on a visual IQ test. I use a large-scale malaria eradication program in Mexico (1957) as a quasi-experiment to prove causality. Basically, I find that individuals born in states with high rates of malaria prior to eradication - the area that gained most from eradication - experienced large gains in IQ test scores after eradication relative those born in states with low pre-intervention malaria rates, areas that did not benefit as much from eradication (see this Marginal Revolution piece for a slightly differently worded explanation).

My paper also looks at the mechanisms linking infections and cognition. One possibility is the biological model described above - infections divert nutritional energy away from brain development. However, I also find evidence of a second possibility: parents respond to initial differences in cognition or health due to early life infections and invest in their children accordingly. In the Mexican data, children who were less afflicted by malaria thanks to the eradication program started school earlier than those who were more afflicted. Because a child's time is the domain of parental choice, this suggests that parents reinforce differences in the way their children are (- erhaps they feel that smarter children will be smarter adults, and so investments in their schooling will yield a higher rate of return - and that this can modulate the relationship between early life experiences and adulthood outcomes.

Good and Bad Epidemiology and Other Interesting Links

2011-10-29T08:29:00.000-04:00

1. The incomparably intelligent and eloquent Sanjay Basu on how doctor house calls of the olden days could return - in the form of targeted efforts to reduce preventative disease and hospitalizations on the basis of cutting edge epidemiology.

2. A man after my own heart, Dr. Ben Goldacare, an evidence based medicine expert, rails against bad epidemiology studies (you know, the kind in the news that like say coffee is protective against cancer or something like this, only to be overturned 180 degrees two months later) in this entertaining TED talk. Some useful pointers about how to differentiate between junk and good research as well as a good summary of causal inference. (HT: Jeremy Green)

3. Apparently there is enough sense to go around for all of us.

4. Asif Mandvi of The Daily Show lampoons the Republican candidates position on science and scientific knowledge in this great clip. Its pretty funny, until you realize that the candidates are actually serious. Then its a little scary. (HT: Kim Kopecky)

5. How does the recession and being out of work influence our physical activity? And what are its implications for health? Gregory Colman and Dhaval Dave explore these issues in an interesting recent NBER working paper.

Discrimination in the Shadows

2011-10-27T10:56:00.001-04:00

Two new papers looking at various aspects of discrimination in product and labor markets. The first, by Ian Ayres and coauthors, examines baseball card sales:

We investigate the impact of seller race in a field experiment involving baseball card auctions on eBay. Photographs showed the cards held by either a dark-skinned/African-American hand or a light-skinned/Caucasian hand. Cards held by African-American sellers sold for approximately 20% ($0.90) less than cards held by Caucasian sellers, and the race effect was more pronounced in sales of minority player cards. Our evidence of race differentials is important because the on-line environment is well controlled (with the absence of confounding tester effects) and because the results show that race effects can persist in a thick real-world market such as eBay.

The second looks at skilled immigrant labor in Canada. Canada, like many other first world countries, has made it a policy to strongly select for skilled immigrants to augment their workforce. Unfortunately, these immigrants do not do as well as one would hope in the labor market. Philip Oreopoulos explores this issue in greater depth:

Thousands of randomly manipulated resumes were sent in response to online job postings in Toronto to investigate why immigrants, allowed in based on skill, struggle in the labor market. The study finds substantial discrimination across a variety of occupations towards applicants with foreign experience or those with Indian, Pakistani, Chinese, and Greek names compared with English names. Listing language fluency, multinational firm experience, education from highly selective schools, or active extracurricular activities had no diminishing effect. Recruiters justify this behavior based on language skill concerns but fail to fully account for offsetting features when listed.

While they speak for themselves, here are a few collective comments on these papers:
1. Both illustrate the power of audit studies, where researchers elicit real-time behavioral responses in the field to some often innocuous stimuli. Resume experiments have a long history in economics and sociology. The EBay thing is new, and quite innovative.
2. Audit studies give us an example of behavior, but can further be extended to think about mechanisms and policy. One reason I like the Oreopoulos paper is that his randomization involved an explicit countersignal to having an immigrant last name. Unfortuntately, it didn't work to reverse the discriminatory effect, but it is informative that signaling language skills failed. What would be nice is to further extend this, both to other policies, but also to a further elucidation of mechanisms. I think qualitative work could be very useful in this regard. (My colleagues and I did this in a paper about corruption).
3. Both of these studies reveal that taste-based or statistical discrimination is pretty deep seated, though it may lurk in the shadows. So what to do about this? Jumping from (2), I hope the next wave of experiments look at different sorts of policies. Are there other nudges that can be used to counteract these forces? Or will immigrants have their change from Shankaranarayan to Steve in order to get jobs?

Building Reflexes

2011-10-24T16:22:00.000-04:00

So I am now a third of the way into my intern year in my internal medicine residency. The whole enterprise started off as a string of stress and self-doubt inducing thought after another: There is a lot to know and I don't think I'll ever know any of it...Wow, that senior resident is really smart. I'm never going to be that good...Dr. So and So is a great attending, I'm never quite going to get there...I've never done a thoracentesis before. What is I mess up?...What if I kill someone?

Of all of the above, a green intern seeing the sheer confidence and competence of the junior and senior residents was somehow the scariest. It was a mystery how someone could go with my fund of knowledge to their fund of knowledge in a year or two. I was convinced I was the imposter in my intern class, the one for whom the physician production process would fail.

Along these lines, as I've moved through intern year, I've learned three important things. All of these have served to keep me sane in the storm of self-doubt:

1. A scared intern is an intern who has an appropriate level of confidence, and therefore thinks harder and is quicker to ask for help. He/she is therefore a safe intern.
2. Every intern feels the same fear coming into residency.
3. The goals of intern year should be modest. Not, "I want to read everything become a master clinician after 1 month on an inpatient service" but "I want to develop quickly implementable algorithms for common clinical situations that will ensure that I am thorough and efficient."

This last aspect is what I call "reflex building." There is a set of clinical situations that interns and residents will face time and time again. Getting good at working up and troubleshooting those problems builds confidence, saves time and allows you to devote your precious tired brain to more intransigent clinical issues.

I remember my first call night where a gentleman became short of breath. I walked into the patient's room, following a frantic nurse, with a veneer of calm but with the insides of a rookie quarterback facing his first test against a wild, aggressive defense. Thoughts scattered, I correctly asked for a stat chest x-ray, ABG kit, had the angle of the bed increased, and called for stat labs. I listened to the chest and thought it sounded wet, and ordered a diuretic. Prior to all this, I paged the teaching senior resident on call.

It turns out I did alright, but I forgot to get an EKG. In my stressed state, I forgot to think about acute cardiac issues (like heart attacks) as precipitants for this new shortness of breath. Clearly, ruling out heart attacks is an absolute must. Luckily the nurses and the night senior all knew what to do and the EKG machine was in the room and humming before I'd even thought to call out for it. (The patient was not having a heart attack.)

Two months later, I was in the same situation. I walked in to the room, again with some outward swag, but this time with also with an organized work-up plan. I got all the tests I needed to get. It turned out the gentleman had missed his diuretic pill for two days. He sounded "wet" and I diuresed him. His EKG was fine and the patient got better quickly. I then had time to leave and deal with the four new admits that hit the floor all at once, then later check in on this patient before I handed off the service to the day team.

It was at that point I realized that I had actually learned a lot during intern year. At any given point in time, the marginal output of the physician production function is hard to observe. That is, at most points in your training, you are faced with such a huge knowledge base that the distance between you and the ideal always looks limitless – you don’t really feel like you are getting anywhere. However, in situations like the one I just described, or where a patient has new urinary retention, new chest pain, a new GI bleed, we've all now seen enough of these to know how to handle these problems efficiently and safely. It’s a great feeling to have these new clinical reflexes.

Some time later, I took on the roll of "running plans" in our inpatient service. Basically, our inpatient service has four interns that take on different roles every day. The "plan runner" goes through each of the twenty or so patients and decides what needs to be done for that day based on that mornings exam and labs, the previous nights events, and all the accruing data about the clinical course. The junior resident, who runs the team, watches over all of this and chimes in and teaches when necessary (which is a lot, early in the year). The first few times I ran plans I got a lot of much needed and much appreciated input from the junior ("Do you really want to do that? And have you thought about this?"). More recently, I’ve been hearing less from them. And I also have a better sense of the nuances the junior needs to know to run the team effectively - how to discharge patients, when not to get labs, how to deal with a difficult consult service. There was one moment, though brief, where I thought to myself “I think I can do that. I think I can be a good junior.”

That was a small, but important, victory.

Ultimately, perhaps the best lesson from all this is to trust in the production process. As our program director put it during orientation, "[The residency program has] been doing this for years. Sit back, put on your seat belt, and let us do our thing. You'll be fine."

Battling the Bulge

2011-10-23T12:55:00.000-04:00

Some innovative social policy this week in Mexico, where the federal government been expressing some palpable alarm over rising obesity among children and adults. I'm sure that Mexico now is the fattest nation in the world and, if they aren't, they are right behind the US in this dubious regard. From a country that was worried about infectious disease deaths just a generation ago to one that is increasingly burdened by diabetes and heart disease comes a new social policy that aggressively seeks to reduce obesity in children by banning junk food, increase hours of physical education, and provide nutritional education in a school based setting. Only time will tell whether they can get people to substitute agua for refrescas, but I like where they are headed with this multi-pronged approach. I know there is some evidence that each of these interventions could provide positive benefits alone (see, for example, here), so perhaps there will be a bigger kick from all three together.

On our side of the border comes some new evidence that your neighborhood matters as far as obesity goes. A study in this week's New England Journal of Medicine finds that poor households randomized to receiving housing vouchers enabling them to move to nicer neighborhoods were significantly less likely to be obese and have elevated hemoglobin A1c levels (a marker of blood sugar content used to diagnose, and track response to treatment for, diabetes). This experiment validates a long-standing hunch that neighborhoods matter for obesity. The question now is what exactly matters, i.e., what is the mechanism behind this causal pathway? We obviously need to know this in order to design targeted policies? Is it that better neighborhoods have better designed streets that encourage walking? The presence of parks? Are there positive peer effects from health nuts? Better grocery stores and more healthy food options relative to junk food options? Better access to primary care docs? I'm awaiting the follow up study which tries to tease these different possibilities apart.

R.I.P Steve Jobs

2011-10-06T10:44:00.000-04:00

"Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. And the only way to do great work is to love what you do" - Jobs, during a 2005 commencement address.

Foreclosures and Health

2011-09-11T14:55:00.001-04:00

Great paper by Janet Currie and Edral Tekin on the housing crisis and its impacts on health outcomes:

We investigate the relationship between foreclosure activity and the health of residents using zip code level longitudinal data. We focus on Arizona, California, Florida, and New Jersey, four states that have been among the hardest hit by the foreclosure crisis. We combine foreclosure data for 2005 to 2009 from RealtyTrac with data on emergency room visits and hospital discharges. Our zip code level quarterly data allow us to control for many potential confounding factors through the inclusion of fixed effects for each zip code as well as for each combination of county, quarter, and year. We find that an increase in the number of foreclosures is associated with increases in medical visits for mental health (anxiety and suicide attempts), for preventable conditions (such as hypertension), and for a broad array of physical complaints that are plausibly stress-related. They are not related to visits for cancer morbidity, which arguably should not respond as rapidly to stress. Foreclosures also have a zero or negative effect on elective procedures, as one might expect. Age specific results suggest that the foreclosure crisis is having its most harmful effects on individuals 20 to 49. We also find that larger effects for African-Americans and Hispanics than for whites, consistent with the perception that minorities have been particularly hard hit.

This study makes a few key contributions to the literature on economic vulnerability and health outcomes. First, it utilizes very detailed data that both enable precise estimates and a number of statistical techniques that can better address potential confounders. Second, the authors make great use of falsification tests. Basically, in theory you would expect stressful events to impact some diseases and not others (especially those that take time to evolve). The authors follow up this idea and actually demonstrate it in their data, which makes the results more believable.

Experiential Learning Versus Thinking Outside the Box

2011-08-20T08:04:00.000-04:00

A typical phone call with my mom involves learning about some of our family friends back home. Invariably, a given set of family friends would have someone my age who I either went to high school with or happened to socialize with in community events. I enjoy these updates because its great to see everyone carving out interesting lives for themselves.

In any case, I recently heard from her about a friend of mine who is now doing an internal medicine residency in Cleveland, OH. This chap was a year ahead of me in high school and someone I really looked up to as I tried to temper and use for good my pre-college pre-med craziness. Like everyone else, I ended up googling him thereafter and came across this really interesting article about a medical school experience of his in the New York Times.

As a physician in training, I am working on developing two skill sets. The first is building enough experiential knowledge in order to recognize important aspects of clinical situations more quickly and thereby reach a diagnostic and treatment pathway earlier on in the clinical encounter. The second is to "think outside the box" and develop a "broad differential diagnosis", meaning one thinks of all of the possibilities why someone might be coming into the hospital to start with and then using the available data to parse out what is more likely to be happening than what is not. Experience is important here, too. As you see more patients, you'll see some weird things, and those will get added to your possibility space as you move forward.

However, I've always wondered whether there are situations where these two skills aren't complementary. The first skill brings forth a form of pattern recognition: "this looks like acute heart failure because I've seen hundreds of these and that was it has to be." This is what experienced clinicians bring to the table. On the other hand, "thinking outside the box" involves convincing yourself that there is a non-zero probability that a rare diagnosis may be driving the picture. This is what medical students are good at, in part because they aren't really taught much about population prevalence and probabilities, evening the playing field between the common and the rare. But I wonder, at least at some points in time, if part of this is also because medical students are not "encumbered" by experiential knowledge. As a result, they can "go outside of the box" because they don't have tunnel vision? They come into a clinical situation with fresh eyes, in some sense like an outside consultant.

The NYT piece about my family friend discusses a situation where more experienced clinicians zeroed in on one particular diagnosis but then were at a loss when they didn't find the evidence to support this. My friend, a fresh wide-eyed third year medical student, was able to think outside the box about a rare illness that could unify all the laboratory results and physical exam findings. He turned out to be right. The piece goes on to discuss the value of a fresh, unadulterated pair of eyes.

I'm barely two months in to my residency, but I've been wondering how to optimize returns to my experiences while at least keeping one eye outside the box. On the other hand, I think, in general, the returns to experience are positive with almost all patients. That is, having more clinical experiences under your belt is usually better. In the other cases, which may be rare, maybe my best bet then is to rely on the fresh supply of medical students and doctors-in-training. Or maybe it actually does make sense for a hospital to have some weirdo like House, MD to outsource bizarre, intractable cases to. We'll each have our comparative advantage and can capitalize on "returns to specialization." Thoughts?

Absolutely Lovely Paper About Esther Duflo

2011-08-19T22:52:00.000-04:00

Esther Duflo, hands down, is one of my favorite economists. Her work spans a rich swath of development economics, touching subjects as diverse (and, ultimately, as related!) as microfinance, education, health care, corruption, women's agency, and, central to a good deal of her work, randomized field experiments. She is also the founder of the Jameel Poverty Action lab and co-wrote the incredible Poor Economics.

Recently, she won the American Economic Association's John Bates Clark Medal, an bi-yearly award given to the topic economist under the age of forty. Chris Udry, one of my favorite professors at Yale, ruminates on Duflo's work in a beautiful essay in the Journal of Economic Perspectives. Reading it, one is amazed about the impact one person can have on an entire field - disruptive technological change at its finest! My favorite part about the piece is how Duflo has remained an incredible academician while also serving as a public intellectual and activist. Excellent stuff.

Great Paper on the Impact of Cancer Screening

2011-08-10T13:27:00.000-04:00

A good number of health care professionals, though perhaps not enough, are obsessed with screening to catch various diseases early - "when we can do more about it." Cancer screening, in particular, is an area of great interest, one that the public has really latched on to over the last 20 years or so. As the row over breast cancer screening illustrates, there is a huge debate on when to screen people. Should we screen at, say, age 40 for breast cancer, or start yearly mammograms at age 50?

It turns out that the evidence to motivate one set of screening guidelines over another isn't all that great. That is, while we know that certain kinds of screening (breast and colon, for example) work, randomized clinical trials of screening tests have too few people in each age group to definitively assess the best age cutoff for these modalities.

Enter this neat paper by Srikanth Kadiyala and Erin Strumpf. They utilize our existing screening guidelines as "natural experiment" to study the effectiveness of screening at the population level. Specifically, while the person aged 39 years old and the person aged 41 years old may be similar in terms of their cancer risk, our national guidelines lead to one person being screened and the other not. Is the 41 year old better off as a result?

U.S. cancer screening guidelines recommend that cancer screening begin for breast cancer at age 40 and for colorectal cancer and prostate cancers at age 50. What are the marginal returns to physician and individual compliance with these cancer screening guidelines? We estimate the marginal benefits by comparing cancer test and cancer detection rates on either side of recommended initiation ages (age 40 for breast cancer, age 50 for colorectal and prostate cancers). Using a regression discontinuity design and self-reported test data from national health surveys, we find test rates for breast, colorectal, and prostate cancer increase at the guideline age thresholds by 78%, 65% and 4%, respectively. Data from cancer registries in twelve U.S. states indicate that cancer detection rates increase at the same thresholds by 25%, 27% and 17%, respectively. We estimate statistically significant effects of screening on breast cancer detection (1.3 cases/1000 screened) at age 40 and colorectal cancer detection (1.8 cases/1000 individuals screened) at age 50. We do not find a statistically significant effect of prostate cancer screening on prostate cancer detection. Fifty and 65 percent of the increases in breast and colorectal case detection, respectively, occur among middle-stage cancers (localized and regional) with the remainder among early-stage (in-situ). Our analysis suggests that the cost of detecting an asymptomatic case of breast cancer at age 40 is approximately $100,000-125,000 and that the cost of detecting an asymptomatic case of colorectal cancer at age 50 is approximately $306,000-313,000. We also find suggestive evidence of mortality benefits due to the increase in U.S. breast cancer screening at age 40 and colorectal cancer screening at age 50.

This is a neat, well-crafted study. The methodology the authors use, called regression discontinuity, utilizes sharp cutoffs in decision rules/policies/etc in the context of otherwise inconsequential changes in the variable used to determine this cutoff (i.e., in the immediate neighborhood of the cutoff). It is a useful way to get quasi-experimental evidence where there is no other way to get it. Indeed, regression discontinuity is now considered second below the gold standard randomized clinical trial in the pantheon of statistical approaches.

Of course, the one problem with this study is that, while we know our existing cutoffs are useful, we don't know if there is some other cutoff that would be better (one of the motivating questions of the paper). Here is a weakness of their research design: unless there is a policy change to a different age cutoff, regression discontinuity will only allow us to evaluate our current guidelines. Either we'll have to turn to evidence from other countries, evidence from different eras - both of which have problems insofar as that the epidemiology and treatment of cancer likely varies across time and space - or turn to larger randomized controlled trials where we can be sure to have large numbers of individuals around the cutoff ages we want to test. Alternatively, we could perhaps exploit current confusion over breast cancer screening guidelines, taking advantage of the fact that some providers may choose age 40 and others 50 to commence yearly mammograms, to assess whether one or the other is better.

Work Hour Limitations for Residents - What Are They Good For?

2011-08-07T23:02:00.001-04:00

I have the (dubious?) distinction of being part of the first cohort of interns who can only work 16 hours at a stretch in the context of an 80 hour work week. These new restrictions were put in place by the American Council for Graduate Medical Education (ACGME) for the purported reasons of reducing medical errors and improving education for first year residents.

These changes come on the heels of a previous set of work hour restrictions put into place in 2004. Prior to that time point residents were pulling long(er) work weeks. Some high profile cases and research into medical errors pointed to the sleepy residence who'd been up 30 hours or something as the culpable party. Hence, residency programs were mandated to have residents work no more than 80 hours on an average week (over some time frame like four weeks).

Interestingly, the data on whether these work hour restrictions produced better outcomes for patients is mixed. Some studies show positive effects on mortality and complications and some show no effect (here's a systematic review from this year covering a whole bunch of studies in the US and UK).

All of this begs two questions: Why did the original work hours restriction not give unambiguously positive effects on patient outcomes? And why the further restriction in 2011, limiting the length of shift to 16 hours?

On the first point, one theory is that compliance to the 80 hour work week was low in residency programs: there was no effect because work hours really didn't decrease. Another explanation is that work hour reductions led to increases in patient "hand-offs." Resident A can't work anymore so resident B might have to take over. If resident A does a poor job telling resident B about a complicated patient, mistakes and bad outcomes become more likely when resident B takes over the caregiving role.

Growing concerns over poor handoffs - and there is some kind of evidence base (see here for an example) now suggesting that handoffs are indeed poor - have prompted many to criticize the ACGME's latest work hour restrictions. If there original work hour restrictions didn't affect patient outcomes, why make any further changes, especially if the number of handoffs increase?

An interesting piece in the NYT a few days ago really gets at the heart of the matter, I think. The author, Darshak Sanghavi, begins deconstructing our obsession with work hour restrictions by examining the case of Libby Zion. In 1984, Zion, a college student, died in an NYC emergency department while being take care of by two residents, one of which was an intern on little sleep. Essentially, a medication error was made that led to a drug interaction that cost Zion her life. The incident became the test case for resident work hour reform, with New York State instituting such reforms first, and the ACGME following suit nationally.

Sanghavi examines this case in detail and notes that there were a multitude of different factors - fragmented outpatient care, poor electronic medical records and decision support, among others - that also could have credibly contributed to Zion's tragic demise. This deconstruction makes a powerful point - sleepy residents may indeed make more errors, but we should be wary of tunnel vision. Other factors deserve consideration. It's a great article and I encourage you to read it (hat tip to OKS for sending it to me).

That said, it may be that the latest work hour restrictions may have some positive effects on patient outcomes. It could be that the real margin of improvement is reducing a given work stretch from 30 to 16 hours, not reducing the total weekly work hours from 100+ to 80. It may also be that less lengthy shifts may reduce burnout and actually allow interns to go home and read something medical. Certainly, there will be a good deal of empirical work on these latest restrictions, and I'll be interested to see which way the axe falls.

(PS: Not sure how much time I'll have to read. One disadvantage of the new restrictions is that it looks like I'll be in the hospital more often during inpatient rotations. In the end, they get you somehow!)

Can Research on Measurement Provide Insights into the Poverty Experience?

2011-08-06T17:14:00.000-04:00

Great paper, forthcoming in the Journal of Development Economics on how the length of recall periods in surveys leads to different measurements of health, wellness and health care seeking behavior. Also interesting is how the recall period length effect differs by income status. The authors use their findings to suggest that experiences with illness have become disturbingly become the normal among the poor vis-a-vis the rich:

Between 2000 and 2002, we followed 1621 individuals in Delhi, India using a combination of weekly and monthly-recall health questionnaires. In 2008, we augmented these data with another 8 weeks of surveys during which households were experimentally allocated to surveys with different recall periods in the second half of the survey. We show that the length of the recall period had a large impact on reported morbidity, doctor visits; time spent sick; whether at least one day of work/school was lost due to sickness and; the reported use of self-medication. The effects are more pronounced among the poor than the rich. In one example, differential recall effects across income groups reverse the sign of the gradient between doctor visits and per-capita expenditures such that the poor use health care providers more than the rich in the weekly recall surveys but less in monthly recall surveys. We hypothesize that illnesses--especially among the poor--are no longer perceived as "extraordinary events" but have become part of “normal” life. We discuss the implications of these results for health survey methodology, and the economic interpretation of sickness in poor populations.

Inaccurate Public Health Messages from Politicians = Very Bad

2011-08-03T18:25:00.000-04:00

Those of you who either follow public health and/or know South Africa have certainly heard about the "AIDS-denialist" bent of former President Mbeki and his Health Minister, Manto Tshabalala-Msimang. If you don't, basically the two of them (mainly the latter with support from the former) put forth a view that HIV does not cause AIDS and that anti-retrovirals on balance confer negative health benefits (see this earlier post). Clearly, this flies in the face of science and common-sense. But what are the effects of these espousals on risky behaviors? Do people actually listen to this stuff? Did these beliefs lead to changes in behavior and, ominously, more HIV infections, in the general public?

A recent paper by Eduard Grebe and Nicoli Nattrass at the University of Cape Town strongly suggests that denialist claims played a role in reducing condom use among a sample of young adults in South Africa. Here's the abstract:

This paper uses multivariate logistic regressions to explore: (1) potential socio-economic, cultural, psychological and political determinants of AIDS conspiracy beliefs among young adults in Cape Town; and (2) whether these beliefs matter for unsafe sex. Membership of a religious organisation reduced the odds of believing AIDS origin conspiracy theories by more than a third, whereas serious psychological distress more than doubled it and belief in witchcraft tripled the odds among Africans. Political factors mattered, but in ways that differed by gender. Tertiary education and relatively high household income reduced the odds of believing AIDS conspiracies for African women (but not men) and trust in President Mbeki's health minister (relative to her successor) increased the odds sevenfold for African men (but not women). Never having heard of the Treatment Action Campaign (TAC), the pro-science activist group that opposed Mbeki on AIDS, tripled the odds of believing AIDS conspiracies for African women (but not men). Controlling for demographic, attitudinal and relationship variables, the odds of using a condom were halved amongst female African AIDS conspiracy believers, whereas for African men, never having heard of TAC and holding AIDS denialist beliefs were the key determinants of unsafe sex.

The study makes a few good points:
1) Bad information can lead to bad public health outcomes. (The ridiculous measles vaccines-autism scare did something very similar, more on that later)
2) These negative effects can depend on the level of education. (Here it is decreasing in education. For the measles vaccine-autism link, more educated people were more likely to decline the vaccine for their kids. Again, more on that later)
3) Social organizations, NGOs and activists can play a major role in reducing the effects of noisy or bad information.

Should Physicians Mind Their (Own) Business?

2011-07-28T21:51:00.000-04:00

A contentious point of debate is the role of physicians in running health care organizations. Some argue that doctors should be in charge of hospitals, given their firsthand knowledge of the realities of clinical medicine and the day-to-day happenstances of caretaking. Others argue that physicians are hopeless at leadership activities in general, that outsiders sometimes have fresh perspectives that sweep away the inertia inherent in a hierarchically structured field like medicine, and point to high profile examples of how executives from other sectors/industries have swept in to save ailing hospital systems (they often refer specifically to Paul Levy, the former CEO at Beth Israel Deaconess in Boston).

So what does the evidence say? Unfortunately, there is very little in the way of hard data on this issue, except for this new paper by Amanda Goodall:

Although it has long been conjectured that having physicians in leadership positions is valuable for hospital performance, there is no published empirical work on the hypothesis. This cross-sectional study reports the first evidence. Data are collected on the top-100 U.S. hospitals in 2009, as identified by a widely-used media-generated ranking of quality, in three specialties: Cancer, Digestive Disorders, and Heart and Heart Surgery. The personal histories of the 300 chief executive officers of these hospitals are then traced by hand. The CEOs are classified into physicians and non-physician managers. The paper finds a strong positive association between the ranked quality of a hospital and whether the CEO is a physician (p<0.001). This kind of cross-sectional evidence does not establish that physician leaders outperform professional managers, but it is consistent with such claims and suggests that this area is now an important one for systematic future research.

As the author suggests, this is but a first step into understanding the returns to a physician versus a non-physician leader. Here are a few thoughts:

1. The main threat to inference in this study is selection into leadership positions. That is, physician and non-physician leaders are not randomly assigned. What if hospitals that are doing poorly, are more desperate, tend to "go outside the box" and hire non-physicians (supposedly, Beth Israel was in this position a decade or more ago). This would create the appearance in the data that non-physician managers do worse, when it reality it is not the case.

One way to push this point is to augment the regression slightly: add a measure of historical hospital quality on the right hand side. That is, regress current quality against current leadership and a measure of quality before that leadership went into place. This would control for selection into quality.

2. Of course, a better design would be to use longitudinal data on quality and leadership and track outcomes over time. A problem with implementing this is that effects only are identified off of those hospitals that change leadership regimes. In addition, rankings need to change over time, too. It's not hard to imagine inertia in both leadership and rankings, limiting the utility of this potential research design.

3. Everyone seems to refer to US rankings as gospel while at the same time denouncing them for their inaccuracy. I think better measures of quality (process elements, for example, like door-to-balloon time, patient satisfaction, etc) may be more informative in better delineating the effectiveness of different kinds of leaders.

4. Finally, there is a growing cadre of physicians who have obtained MBAs, MHAs, MPPs, MPHs. Are these dual-degreed souls better leaders than MD only physicians or non-MDs (I suspect the answer is yes)? I'd be interested to know.

Random Links

2011-07-19T13:27:00.000-04:00

1. "Frying big fish" - My colleague and good friend Paul Lagunes has a wonderful piece on the problem of, and solutions to, police corruption.

2. A trip across one of the bridges crossing Chennai's Buckingham Canal brings the familiar site of people defecating along the side of the road. Clearly a public health program. Karen Grepin on how the Gates' Foundation is bringing this to public attention.

3. A piece on sportswriter Bill Simmons' new website "Grantland" about the genius that is Friday Night Lights. I love how the article is structured as an "oral history."

Expanding Medicaid - Good, Bad, or Ugly?

2011-07-12T18:57:00.000-04:00

Possibly the most important health economics paper of the year, especially as it relates to the debates surrounding Obamacare. Here is the abstract:

In 2008, a group of uninsured low-income adults in Oregon was selected by lottery to be given the chance to apply for Medicaid. This lottery provides a unique opportunity to gauge the effects of expanding access to public health insurance on the health care use, financial strain, and health of low-income adults using a randomized controlled design. In the year after random assignment, the treatment group selected by the lottery was about 25 percentage points more likely to have insurance than the control group that was not selected. We find that in this first year, the treatment group had substantively and statistically significantly higher health care utilization (including primary and preventive care as well as hospitalizations), lower out-of-pocket medical expenditures and medical debt (including fewer bills sent to collection), and better self-reported physical and mental health than the control group.

Some quick thoughts:
-Possibly one of the first randomized studies to show a positive impact of insurance on self-reported well-being. While some may pooh-pooh at the fact that the effects were on self-reported health rather than objective measures, I would argue that such subjective measures are equally, if not more, important.

-The randomized design obviously gives you a solid estimate of the average treatment effect for this population. However, Oregon is a unique place and the people targeted were unique, as well (low-income people who were aching for insurance). It remains to be seen if this result would generalize elsewhere.

-These effects are for 1 year out. It would be interesting to see how this all fares in the medium and long-run. Would increased preventative and primary care utilization now lead to cost-savings down the road? One would hope.

Global Health Data Exchange [!]

2011-07-10T12:42:00.000-04:00

For your viewing and researching pleasure. The data exchange is courtesy of the University of Washington's Institute for Health Metrics and Evaluation. The goal is to collect all the random and not-so-random datasets floating around out there, thereby creating a "one-stop shopping" space for those interested in both tabulated and raw (census, survey, macro-health) data.

I found out about this just today while reading Sanjay Basu's latest blog post (a good one on global health data sources), and spent a better part of the browsing the site. At a first pass, the data exchange seems really comprehensive. As a grad student, I prided myself on knowing about every random dataset out there, something that took a lot of effort and time. Now, there is a nice, comprehensive external brain for such an endeavor. I hope this project continues along its current trajectory because it has a ton of promise. I would say that even in its current state it will prove quite useful for interested lay-people, policymakers, and hard-core researchers alike.

Noisy/Bad Information and Health Care Decisions

2011-07-08T14:54:00.000-04:00

There was an interesting post on the Wall Street Journal's Health Blog about medical professionals and the use of social networks a few days ago. Much of it dealt with issues related to privacy (don't tweet about interesting cases in a manner that might identify patients, etc). However, I thought the most interesting part came at the end:

Montori says institutions and practitioners can raise awareness about conditions or available treatments, and also to counteract misinformation floating around online [using social networks]. “A lot of my colleagues say they don’t have time for distractions” like social media, he says. “But if folks who are really on the front lines of care cannot engage in this space, their thoughts, insights and experience will not be flowing through the network.”

And meantime, Montori says, “the thoughts of those who aren’t that busy, or who are paid to be in that space” will dominate. “Patients are receiving what they think is a signal but in fact it’s noise,” he says.

That last bit, about noisy signals, is an important one. It turns out that when health care professionals provide incorrect information, people learn from it in a way that is counterproductive. One of the most poignant illustrations of this comes from my friend and colleage Achyuta Adhvaryu, an economist who works on global health issues at Yale University. Adhvaryu was struck by how slowly people adopted new, highly effective anti-malarials in Tanzania after a brisk rate of uptake in the first year they were available. This is all the more weird given what we know about what malaria does to economic productivity.

Using an elegant and convincing set of theoretical and empirical techniques, he uncovers an interesting phenomenon: adoption rates are far lower in areas where the rate of misdiagnosis is higher. The story goes something like this: you have a fever, and go seek treatment. You get diagnosed with malaria and handed antimalarials. Now, if you actually have malaria, the treatment will make you feel better and you'll learn from that experience. If you don't have malaria, the treatment won't really help you and you'll lose belief in the new therapy. Adhvaryu's estimates suggests that this misdiagnosis effect is quite large and important.

We remain very interested in why people in developing countries don't adopt things like better vaccinations, malarial bednets, circumcision, etc. At a first glance, failure to adopt these cheap but potentially life-saving/enhancing interventions seem irrational. However, in a world where people respond to information, good or bad, accuracy in education and diagnosis can go a long way in encouraging socially optimal behaviors.

By the way, this is not just a developing country issue. When the medical journal Lancet (irresponsibly in my opinion) published a startlingly dubious study linking measles vaccines to autism, a non-trivial number of people stopped vaccinating their kids. It all seems silly, but it emphasizes greatly the role of information, good or bad, in the decision making process.

Bad Epidemiology

2011-07-07T21:33:00.000-04:00

While in South Africa a few months ago, an irritating yet clever radio announcer, during a joke-based interlude between songs, made the following comment:

"Research has shown that insomnia leads to depression. Other research has shown that depression leads to insomnia. Still other research has shown that research leads to more research."

Seems like a great indictment of some of less-than-careful, data mining-y studies that often find their way into decent journals and on the evening new. (Note: I'm not anti-epidemiology.)

More on Corruption in the Public Sector

2011-06-29T21:59:00.000-04:00

This time the relationship between elections and corruption. Suprise surprise, but elected officials respond to incentives, too:

We show that political institutions affect corruption levels. We use corruption audit reports in Brazil to construct new measures of political corruption in local governments and test whether electoral accountability affects the corruption practices of incumbent politicians. We find significantly less corruption in municipalities where mayors can get reelected. Mayors with re-election incentives misappropriate 27 percent fewer resources than mayors without re-election incentives. These effects are more pronounced among municipalities with less access to information and where the likelihood of judicial punishment is lower. Overall our findings suggest that electoral rules that enhance political accountability play a crucial role in constraining politician’s corrupt behavior.

Great paper, and in the June 2011 issue of the American Economic Review.

The Persistence of Inequalities at Birth

2011-06-28T23:27:00.001-04:00

The Economix blog at the New York Times has a great post on how differences in birth weight early in life lead to persistent differences in well-being (measured any way you'd like) in adulthood.

The article does a great job of highlighting studies exploring the causes of birthweight differences. Some of them are somewhat unexpected: did you know that EZ-pass is associated with higher birth weights and less risk of prematurity? (Hat tip: AKN)

Comparative Effectiveness Research - What is it Good For?

2011-06-26T08:52:00.000-04:00

One oft floated solution to rising health care costs is the use of comparative effectiveness research (CER) to guide use of more efficient/efficacious therapies from the outset, reducing the need for costly readmission, diagnostic tests and trials of different therapies. CER involves a set of tools that help compare two or more different treatment strategies with each other, often in the context of a randomized clinical trial. An added wrinkle to all this is the the (in)famous Cost Effectiveness Study (CEX), where the outcome returns to different treatments are scaled/compared by their cost.

While proponents of CER are gung-ho about its clinical and policy utility, there are potential downsides to such research. In general, most of our clinical trials recover average effects for a population of interest. That is, we compare drug X against drug Y in randomized groups of 15-75 year olds with certain manifestations of disease Z. This is great for getting an average effect estimate for a particular population. That is, if we randomly draw a 15-75 year old with certain manifestations of disease Z, on average we can expect drug X and Y to work a certain way.

However, there is an increasing realization that drugs work differently for different people. Individuals may vary in the manner in which they metabolize certain drugs or the nature of their underlying illness, while equivalent to the average clinician, may differ in its responsiveness to treatment (see here for a great discussion on this.) If this is the case, widespread use of CER and CEX may not make people better off. In some cases, it might make some people worse off. For example, if some people are better off with drug X, but the average person benefits more from drug Y, the use of the latter will make some people worse off.

In a very interesting paper (see here for a non-gated, older version), Anirban Basu, Anupam Jena,and Tomas Philipson provide a real clinical example of this latter point from psychiatry. They build a model where CER and CEX information is used by insurers/payers to guide clinical care. That is, when a study comes out showing that drug Y > X, these parties are only willing to pay from drug Y. They then show that, in the case of schizophrenia, overall health may have been reduced because people who were formally doing well on drug X were forced to take drug Y, which was actually worse for their health and well-being. The authors go on to call for a more nuanced understanding of how CER and CEX research can be used to guide treatment, especially in an era where individualized treatments are becoming more popular (Basu has a great essay on this point here; see here for a technical paper on how CER can be individualized). Certainly, a regime where CER/CEX can be maximally useful will involve directed clinical trials that take heterogeneous treatment effects into account in the a priori design.

(PS: A great summary essay on CER/CEX, which covers many of the above points, can be found in a recent issue of the Journal of Economic Perspectives. Also, hat tip to AKN for bringing several of these papers to my attention.)

Random Links

2011-06-25T18:55:00.000-04:00

1. Al Gore comes out in favor of access to better health care, family planning services, and education, especially targeted towards women, as a strategy towards improving well-being in the developing world. All sensible stuff. Unfortunately, echoing the vitriol of family planning debates over the last half century or more, he was mistakenly, hilariously, and sadly criticized for being a eugenicist and/or Malthusian by some conservatives.

2. Chris Blattman on a great new paper linking weather disturbances/changes faced early in life to long-run outcomes. He makes some great points about the mechanisms underlying these relationships as well as appropriate practices for statistical work when researchers have abundant data points but little theory guiding exactly what the relationship between two variables might be.

3. Some time ago, I wrote about tennis rackets, lamenting the disappearance of one model in particular as if it were a lost love. Apparently, that tone was appropriate since the racket a pro tennis player chooses seems to say a lot about their personality and preferences - at least as it relates to the tennis court . (Hat tip: MG)

4. I just found out that Sanjay Basu, an MD/PhD epidemiologist doing an internal medicine residency at UCSF, has a great thing going with his new(-ish) blog, epianalysis. Sanjay has got to be one of the most talented, insightful and prolific researchers around. His work spans the mathematical modeling of infectious diseases that incorporate insights from fields as diverse as economics and epidemiology, all the way to deep political economy issues related to global health. He's produced a body of work while in residency that I would be proud of if it formed the entirety of my research career. Seriously. His blog is phenomenal and highly recommended. (Hat tip: PC)

Sex and Measurement

2011-06-22T23:20:00.000-04:00

We know with a good deal of certainty that unprotected sex exposes individuals to potentially life-threatening illness. We also know that all sexual encounters are not the same and, especially since the HIV/AIDS epidemic, researchers have been trying to figure out what sexual behaviors are riskiest and how to use this information towards better micro and macro-focused prevention efforts.

As with all research, a key issue is measurement. Our models to predict individual behavior are usually only as good as our data. As you might imagine, sex can be a personal topic. One may be reluctant to tell a survey interviewer/doctor/friend about their sexual activities, obscuring the whos, hows and whens that are oh-so-important for public health.

Some recent work provides insight into the scale of the measurement problem. A paper by Alexandra Minnis and colleagues compared self-reported sexual activity with biomarkers of exposure (a test based on PSA which can detect exposure to semen in the previous two days) in a sample of Zimbabwean women. The results were sobering: 52% of women who had positive biomarkers said that they engaged in protected sex in the last two days; 23% reported having no sex at all!

In another paper, Brendan Maughan-Brown and I looked at a sample of young adults in Cape Town, South Africa. Our study focused on concurrent sexual partnerships, intuitively defined as the presence of (temporal) overlap between sexual relationships with two distinct partners. There is a hot debate right now on whether such partnerships have been driving the HIV/AIDS epidemic in sub-Saharan Africa. Unfortunately, this debate has been held back by the availability of good data.

Recently, UNAIDS came out with some guidelines on how to standardize and better measure concurrency. We assessed the effectiveness of these guidelines by assessing whether individuals who reported having concurrent relations also reported more than one sexual partner. What we found was surprising: among those who reported only one sexual partner in the last year, nearly 1 out of 6 reported having concurrent sexual relations during this period! We conclude that the UNAIDS methods, which involves asking individuals about each sexual partner they've had and the start and end dates of those partnerships, may actually underestimate the prevalence of concurrency by a significant amount by not fully accounting for all sexual partners.

As both these papers suggest, we have a long way to go before we can credibly claim that we have precise, unbiased estimates of sexual behavior. It would be useful to divert some of time we all spend on linking specific sexual behaviors to health outcomes to figuring out how to get the measurements of those behaviors right in the first place.

A Poignant Opening to the Innings

2011-06-14T22:40:00.000-04:00

Today was the second of a 10-day orientation to my internal medicine residency. It's a bit like summer camp right now: the schedule is friendly, the people are even more friendly, and everyone is smiles and giggles. It's been celebratory as well, as if a continuing acknowledgment of our finishing medical school. However, I snapped out of this post-medical school graduation reverie this afternoon when I met one of my future patients.

While I was visiting my to-be clinic site with three to-be colleagues, an African-American gentleman in a baseball cap, who had been watching me while on a tour of the facility, came up to me and plainly stated: "So, you're my doctor." I must have looked at him blankly because he followed it up by saying: "You're the guy with the really long name right? You're my doctor."

I was a bit taken aback, until I realized that this nice gentleman was indeed going to be one of my patients. Every year, my internal medicine program graduates a class of residents. Each resident has a panel of outpatients that they have taken care of over the three years of the program. At the end of residency they turn their panels over to one of the incoming interns. This particular patient is one of the 100 or so I'll be "inheriting" from my senior.

"My doc told me that she's leaving and that you're the new guy," he went onto explain, "So...what is your name?" I started out by saying, "Hey, I'm Atheen" - and then I caught myself. "I'm Doctor Atheendar" I told him, steadying my voice. I gave him a firm handshake, too, instinctively, yet still theatrically moving my left hand over to additionally grasp his right, as if to say "yeah, I'm new - but I got this." Being so unsure about my abilities, knowledge and competence as a physician-in-training, I thought I saw a hint of skepticism in his eyes. But it couldn't have been, because he suddenly smiled broadly and stated proudly, as he looked at the nurse nearby, "HE is my doctor."

And so I am. And so it begins - humbling and inspiring, all at once.

Good Articles on US Health Care

2011-06-05T09:23:00.000-04:00

The most recent issue of the Journal of Economic Perspectives contains some excellent articles related to health care reform. The articles cover everything from the effects of medical malpractice reform to the impacts of payment structures to physicians on cost growth. All of the articles are written by top health economists with a great deal of research and policy experience. My two favorite pieces examine the role of administrative costs in explaining cross-country differences in health care expenditures and the future of comparative effectiveness (and cost-effectiveness) research in health care decision making. Definitely check it out!

Poor Economics

2011-05-25T12:58:00.000-04:00

I am working through this great book by MIT economists Abhijit Banerjee and Esther Duflo called Poor Economics. This beautifully written tome goes through various problems in economic development and discusses how evidence from the fast growing array of randomized field experiments in development economics can be used towards designing incisive policy interventions. What I love about this book is that it is theoretical and practical all at once. While there is still a healthy debate over the utility of experiments in development economics (see this recent post by Chris Blattman, and this one), what can't be argued is the importance of this methodology as at least a complementary tool in our quest to understand why some places are poor and others are not.

One of my favorite aspects of this new book is the accompanying website (linked above). In addition to access to various tables and datasets for 18 different countries, the website has a link to lectures on Banerjee and Duflo. The lectures on health, in particular, are quite interesting: they cover prevention, deworming, the importance of information, and the role of health in development. Some of these are practical resources that would be highly useful for health care practitioners who are interested in global health.

Lost in the Mail

2011-05-24T10:33:00.000-04:00

I just read an interesting paper by Marco Castillo and coauthors on crime in Peru. The study involves a field experiment where the researchers sent out a bunch of envelopes to people involved in the experiment. They signaled the presence of valuable items in the envelopes by making them thicker and/or implying that the letters were sent between relatives (who might be more likely to send valuable things).

This is a clever paper with three really interesting findings:
1) 18% of the envelopes never made it to their destination.
2) Thicker envelopes and those addressed to putative relatives were far less likely to make it.
3) Mail sent to poor neighborhoods did not make it to its destination 18% of the time and mail sent to really rich neighborhoods failed to arrive about 10% of the time. Where most of the mail was lost is in middle income neighborhood. Apparently, this is where the trade-off between the expected value of the envelope contents and the risk of facing retribution due to complaints from influential people is maximized.

Here's the kicker: Peru's mail system is privatized. While privatization is often tossed around as a solution to inefficiencies in developing countries, this paper makes the great point that such changes may have little impact if employees in the system are not held accountable. Ultimately, bad incentives are bad incentives are bad incentives.

Write Our Future...

2011-05-23T11:00:00.000-04:00

...is the name of a fantastic NGO that my good friends Brendan and Rebecca Maughan-Brown have started in South Africa (you may recognize Brendan as a frequent co-author of mine in previous posts). The broad goal of WoF is to intervene on disadvantaged children in South Africa to improve health, nutrition and education.

Currently, the Maughan-Browns are working towards providing school-based meals for 100 children for an entire year in the Eastern Cape, where budget issues have led to the cessation of a government-funded program doing the same. It's a great cause, as school meals have been shown to increase attendance and perhaps even test scores, both of which can have important long-run benefits.

I encourage you to donate if you are interested. The Maughan-Browns are smart people looking for evidence-based, high impact interventions. They are running WoF with low overheads, guaranteeing that your money is well spent.

The Internet and Prescription Drug Abuse

2011-05-22T11:04:00.001-04:00

Abuse of prescription drugs has grown markedly over the last decade or so. Some have argued that this is due to the growth in online pharmacies, particularly ones that do not require physician visits prior to dispensing medications or, more ominously, ones that do not require any physician approval or prescription or even questionnaires to assess medical histories.

A recent paper by Anupam Jena and Dana Goldman argues that this connection might be quite real. The authors find that a 10% increase in the use of high speed internet - which increases access to online pharmacies - at the state level is associated with a 1% increase in admissions to treatment facilities for prescription drug use. Importantly, this finding is robust to a variety of falsification checks. In particular, the authors show that admissions for abuse of other drugs, such as cocaine and alcohol, whose purchase is unlikely to be linked to access to internet, did not rise with the proliferation of internet during the same time period.

Interesting Global Health Policy Articles

2010-02-16T20:35:00.000-05:00

The January 2010 issue of PLoS Medicine contains four interesting articles on the "global health system" The articles define what this system is, discusses the role of nations within this larger system and talks about how to strengthen it's effectiveness. These pieces are written by leaders in the field and provide some concrete discussion on a concept that has gained currency over the last few years, that global health is a policy domain of importance and that nations can be thought interlinked as part of a larger "health ecology" when developing policies to address morbidity and mortality the world over.

For more on global health and global health governance, you may want to check out this interview of one of my thesis committee members, Yale University Professor Jennifer Prah Ruger. Her work (linked here) focuses on this broader global health system, linking insights from ethics, politics, policy and economics to understand how and when investments in international health are and should be made.

Finally, for a topical piece on health care worker shortages worldwide, and the role of the United States in alleviating these, see this great essay by Yale medical student (and my former roommate!) Dayo Fadelu.

Non-Technical Introduction to Causal Inference/Methods

2010-02-15T08:59:00.001-05:00

Hi everyone, the blog is back in business.

I recently came across a great working paper seeking to introduce econometric methods geared towards understanding causality to a non-expert audience. I'm particularly excited about this because I think many of these methods could really be useful in medical care/clinical questions where it is either unethical or technically difficult to randomize patients (and yes, there are still plenty of those!). For whatever reason, these methods are, in my estimation, rather underutilized in medicine.

Obviously, while the linked piece is geared towards education policy, the methods can be used in any context. Here is the abstract:

Education policy-makers and practitioners want to know which policies and practices can best achieve their goals. But research that can inform evidence-based policy often requires complex methods to distinguish causation from accidental association. Avoiding econometric jargon and technical detail, this paper explains the main idea and intuition of leading empirical strategies devised to identify causal impacts and illustrates their use with real-world examples. It covers six evaluation methods: controlled experiments, lotteries of oversubscribed programs, instrumental variables, regression discontinuities, differences-in-differences, and panel-data techniques. Illustrating applications include evaluations of early-childhood interventions, voucher lotteries, funding programs for disadvantaged, and compulsory-school and tracking reforms.

Enjoy!

The Long-Arm of Childhood Exposure to War

2009-09-25T16:00:00.001-04:00

As if war wasn't destructive enough, a new working paper by Mevlude Akbulut-Yuksel at Dalhousie University finds that childhood exposure to conflict-induced destruction has a wide variety of consequences in adulthood:

During World War II, more than one-half million tons of bombs were dropped in aerial raids on German cities, destroying about one-third of the total housing stock nationwide. This paper provides causal evidence on long-term consequences of large-scale physical destruction on the educational attainment, health status and labor market outcomes of German children. I combine a unique dataset on city-level destruction in Germany caused by Allied Air Forces bombing during WWII with individual survey data from the German Socio-Economic Panel (GSOEP). My identification strategy exploits the plausibly exogenous city-by-cohort variation in the intensity of WWII destruction as a unique quasi-experiment. My findings suggest significant, long-lasting detrimental effects on the human capital formation, health and labor market outcomes of Germans who were at school-age during WWII. First, these children had 0.4 fewer years of schooling on average in adulthood, with those in the most hard-h! it cities completing 1.2 fewer years. Second, these children were about half inches (one centimeter) shorter and had lower self-reported health satisfaction in adulthood. Third, their future labor market earnings decreased by 6% on average due to exposure to wartime physical destruction. These results survive using alternative samples and specifications, including controlling for migration. Moreover, a control experiment using older cohorts who were not school-aged during WWII reveals no significant city-specific cohort trends. An important channel for the effect of destruction on educational attainment appears to be the destruction of schools and the absence of teachers, whereas malnutrition and destruction of health facilities during WWII seem to be important for the estimated impact on health.

Psychiatric Pharmacotherapy and Crime

2009-09-21T19:03:00.000-04:00

I'm now on my psychiatry rotation, and it would be an understatement to say that it has been interesting. Washington University is a big believer in biological models of psychiatric diseases - which means I need to have a good command of neurobiology and pharmacology to really understand what is going on with the ward patients - and this sentiment has grown more generally in the last 20-25 years.

One of the things we are taught in terms of epidemiology is the link between psychiatric disease and crime. As such, from a health policy standpoint, if we are trying to understand the net social impact of pharmacotherapy for psychiatric disease, we need to understand the impacts this may have on crime in addition to disease burden. A new working paper by Dave Marcotte and Sara Markowitz attempts to look into this issue:

In this paper we consider possible links between the advent and diffusion of a number of new psychiatric pharmaceutical therapies and crime rates. We describe recent trends in crime and review the evidence showing mental illness as a clear risk factor both for criminal behavior and victimization. We then briefly summarize the development of a number of new pharmaceutical therapies for the treatment of mental illness which diffused during the “great American crime decline.” We examine limited international data, as well as more detailed American data to assess the relationship between crime rates and rates of prescriptions of the main categories of psychotropic drugs, while controlling for other factors which may explain trends in crime rates. We find that increases in prescriptions for psychiatric drugs in general are associated with decreases in violent crime, with the largest impacts associated with new generation antidepressants and stimulants used to treat ADHD. Our estimates imply that about 12 percent of the recent crime drop was due to expanded mental health treatment.

As you can imagine, the authors have to work pretty hard to deal with all the unobserved heterogeneity/confounding that might lead to the spurious estimates of the treatment-drug relationship. I think the authors do a decent job (though any analysis of this sort will have limitations) and the 12% number, while seemingly high, is still lower than postulated impacts of other sources of the crime decline (abortion, reductions in lead exposure), and enough so that it actually sounds plausible.

Variance in Physician Behaviors

2009-09-19T10:59:00.001-04:00

I just finished my internal medicine clerkship a week ago. One of the more frustrating yet interesting things I noticed was how one attending physician would praise me for a suggestion while another would gently chastise me for making the same point. That physician behavior varies from one area to the next is well known. However, the kind of variation I experienced - within area variation is less well studied. This sort of variation is equally interesting and important for policy. Do physicians in the same area vary in practice styles because of their baseline experiences and subsequent Bayesian updating? Will physicians converge to the same set of practices or beliefs by learning from their peers?

Andrew Epstein and Sean Nicholson attempt to quantify and explain within area variation in an interesting paper forthcoming in the Journal of Health Economics. From their abstract:

Small-area-variation studies have shown that physician treatment styles differ substantially both between and within markets, controlling for patient characteristics. Using a data set containing the universe of deliveries in Florida over a 12-year period with consistent physician identifiers and a rich set of patient characteristics, we examine why treatment styles differ across obstetricians at a point in time, and why styles change over time. We find that the variation in c-section rates across physicians within a market is two to three times greater than the variation between markets. Surprisingly, residency programs explain less than four percent of the variation between physicians in their risk-adjusted c-section rates, even among newly-trained physicians. Although we find evidence that physicians, especially relatively inexperienced ones, learn from their peers, they do not substantially revise their prior beliefs regarding how patients should be treated due to the local exchange of information. Our results indicate that physicians are not likely to converge over time to a community standard; thus, within-market variation in treatment styles is likely to persist.

What is fascinating is that (a) early-career variation in treatment styles cannot be explained by the place and nature of training and (b) that while there is considerable cross talk across attending physicians, doctors are reluctant to change their beliefs. This makes things difficult from a policy standpoint: how do you get physicians on board with new guidelines or encourage local diffusion of best practices when the rate of change is so slow and the variation apparently idiosyncratic?

How the Steelers Can Win An Additional Game this Season

2009-09-16T18:03:00.000-04:00

Fall means football, and the NFL season started off in full force last Saturday. Like any well-invested football fan, I've been following every piece of gossip and analysis in a futile attempt to predict outcomes and will the Pittsburgh Steelers to victory.

Interestingly, the most intriguing analysis of the year to date has come from a pair of economists, which includes Steve Levitt of Freakonomics fame. They write:

Game theory makes strong predictions about how individuals should behave in two player, zero sum games. When players follow a mixed strategy, equilibrium payoffs should be equalized across actions, and choices should be serially uncorrelated. Laboratory experiments have generated large and systematic deviations from the minimax predictions. Data gleaned from real-world settings have been more consistent with minimax, but these latter studies have often been based on small samples with low power to reject. In this paper, we explore minimax play in two high stakes, real world settings that are data rich: choice of pitch type in Major League Baseball and whether to run or pass in the National Football League. We observe more than three million pitches in baseball and 125,000 play choices for football. We find systematic deviations from minimax play in both data sets. Pitchers appear to throw too many fastballs; football teams pass less than they should. In both sports, there is negative serial correlation in play calling. Back of the envelope calculations suggest that correcting these decision making errors could be worth as many as two additional victories a year to a Major League Baseball franchise, and more than a half win per season for a professional football team.

Interesting stuff. I wonder if this article will garner as much controversy as a piece written a few years back by economist David Romer, whose analysis suggested that NFL teams play a risk-averse, sub-optimal strategy when punting the football outside of their own red zone.

Life Expectancy, US Health Care and Other Interesting Links

2009-08-08T20:13:00.000-04:00

1. Samuel Preston and Jessica Y Ho on how reduced life expectancy in the United States need not implicate the health care system. I pointed out a similar argument in an earlier post. Here's a more spirited defense from Gary Becker.

2. Richard Posner and Gary Becker on the obesity epidemic, both making interesting, but not completely persuasive arguments. Posner argues that the growth in obesity, as well as its correlation with education, can be explained by a lack of information about the harms of fatty or calorie-laden foods. He argues that this implies that prevention campaigns that warn people of the dangers of fatty foods (through, for example, calorie labeling) are the best way to tackle the obesity epidemic.

Becker does not buy this (taking a not-so-subtle sweep at behavioral economics along the way), arguing that a fully-informed rational agent model can explain trends in body-weight. In particular, he argues that the development of effective pharmacotherapy for diseases like diabetes, hypertension and coronary artery disease may dissuade individuals from giving up unhealthy foods since the future cost of consumption are attenuated. He also criticizes Posner's position that obese individuals confer externalities on other members of society.

3. The NBER has a set of links to video lectures by John List and Michael Kremer on field experiments in economics and in developing countries, respectively. I've seen the latter set and it is quite good.

World Oil Prices and Child Health

2009-07-27T19:40:00.000-04:00

Yale Political Science graduate student Brian Fried and I have a new working paper looking at how fluctuations in world fuel prices impact child respiratory health. Here is the abstract:

Acute respiratory infections secondary to indoor air pollution from the use biomass fuels such as wood, dung and crop residues, are an important but under-explored cause of morbidity and mortality among children in the developing world. Designing policies to address this issue requires an understanding of the determinants of household fuel choice. This study explores one particular determinant, fluctuations in world fuel prices, which impact the local prices of clean-burning fuels such as liquid propane gasoline (LPG). Using a rich, nationally representative survey dataset from Guatemala, we explored the association between shocks to world fuel prices, measures of household biomass fuel use, and the respiratory health of children under the age of six. Our core finding was that a $1 (3.6%) increase in the (one week lagged) world oil price was associated with nearly a 3 percentage point increase in the likelihood of a child under the age of six experiencing respiratory symptoms. This association is likely driven by changes in household fuel use: increases in oil prices were associated with increases in the time spent cooking by the child’s mother and by the likelihood that the household collected firewood, both of which indicate a switch to biomass fuels. In addition, the fuel price effect on child respiratory health was strongest among very young children, who are more dependent on their mothers and therefore are more exposed to cooking smoke, and was nonexistent in areas that did not have markets for LPG, where substitution across clean and dirty fuels is not possible. Our results have important implications for policies aimed at reducing the burden of disease from respiratory illnesses secondary to exposure to pollutants from biomass fuels.

Worthy Links on Health Care Reform

2009-07-24T22:36:00.000-04:00

1. An article in Slate about physician incentives and their relationship to salary, all in the context of health care reform. The punchline: health care reform likely won't make a dent in physician reimbursement given the power of the doctor lobby and that fact that the government cannot interfere easily when much of health care is funded privately. I think the former point is true, and very sad, since doctors need to realize they respond to incentives just like anyone else. The latter seems like an overstatement: a fair amount of health care dollars (45%) come from public sources. Not a typo.

2. Another interesting piece in Slate, measuring up the US health care reform against our nation's deepest core economic and social values. The juxtaposition is interesting because it is at once jarring and at once perfectly consistent. I will let you read the piece to see what I mean. It's completely worth it: I haven't seen the health care reform debate phrased in this manner and it's definitely a refreshing perspective.

Economic Shocks, Risky Sexual Behavior and the HIV/AIDS Epidemic

2009-07-19T19:58:00.000-04:00

The relationship between poverty and HIV/AIDS is a tricky one to pin down empirically. Studies have found widely different associations between SES and the likelihood of having been infected, though the positive association between education and HIV risk appears to be stable across time and space (see this excellent paper by Jane Fortson).

Aside from permanent economic status, transitory shocks may have some impact on the HIV/AIDS epidemic, as well. The idea is that bad times may induce people to engage in riskier sex because of market returns to such behaviors. The possibility of transient shocks in driving sexual behavior and, consequently, the HIV/AIDS epidemic is an intriguing one, especially given the potential prominence of "transactional sex" - sex in exchange for gifts, favors, etc (i.e., not necessarily prostitution!) - in African countries.

Two recent papers having examined this issue in the context of commercial sex workers. A study by Pascaline Dupas and Jonathan Robinson looks at the effects of political instability in Kenya circa 2007, which led to civil conflict and adverse economic times, on the behavior of commercial sex workers (CSWs). They find that CSWs were more likely to engage in unprotected sex after the adverse shock. A paper by Robinson and Ethan Yeh tells a similar story: CSWs in Kenya were more likely to have a variety of different types of riskier sex in response to income shocks. Both of these studies are well done from the stand point of data collection (how many people have panel data on CSWs??) and statistics (causality is plausibly inferred from both pieces).

In some African countries, however, CSW is not a common practice while transactional sex, more broadly, is. In such areas, it would be interesting to look at how the sexual behaviors of the general population respond to income shocks. My colleague Brendan Maughan-Brown, from the University of Cape Town, and I are working on this in the context of Khayelitsha, a township of Cape Town, SA, where antenatal clinic data indicates an HIV/AIDS of over 30%. Using longitudinal data from an effectively random sample of the township, we found (from individual fixed effects models) that people responded to income shocks by reducing condom usage. Interestingly, we found the same result when looking at individuals who were on anti-retroviral therapy for HIV/AIDS (draft forthcoming - will keep you posted).

We are currently trying to understand whether our results reflect a price mechanism (individuals cannot afford to pay the cost of obtaining and using condoms during bad times) or a consumption smoothing mechanism (individuals engage in riskier sex to get by during bad times). Either way, we have compelling evidence that economic shocks may play a role in driving the HIV/AIDS epidemic.

"Sin Taxes," Public Health, and Targeting

2009-07-14T10:17:00.000-04:00

"Sin taxes" have been all the rage for some time, with the idea being that people respond to hikes in the prices of various deleterious substances by reducing their unhealthy behaviors. Taxes on goods such as tobacco and alcohol are often justified on the grounds that people's unhealthy behaviors have social costs: one man's boozing and smoking adversely affects those around him.

Conventional wisdom suggests that, on average, such taxes work. However, taxes may work differently for different people. As far as health promotion, one would expect sin taxes to be most powerful if they can effectively help change among individuals who have more severe and intractable problems with smoking and drinking.

Some of my colleagues at Yale (including two of my advisers, Jason Fletcher and Jody Sindelar) have produced some interesting work looking into the effectiveness of tobacco and alcohol taxes on different types of smokers and drinkers, respectively. To explore heterogeneity among smokers and drinkers, they use a latent class method (finite mixture models - discussed two posts ago) to identify different groups of people. What the find is striking: for tobacco use among adolescents and alcohol use among adults, taxes are least effective among groups that tend to smoke or drink more heavily and who generally have the least willpower to quit. The authors make use of very detailed data on people's behaviors, preferences and outlook on life to build these interesting stories.

The results suggest that, among those least likely to quit on their own, taxes appear to have little power in inducing behavior change. Basically, from a public health standpoint, if one is interested in reducing unhealthy behaviors in these populations, policies other than/in addition to taxes will likely be required.

Two Year Anniversary

2009-07-12T21:31:00.000-04:00

Having found myself short on sleep and time over the last few weeks, I forgot to write a note here about the two year anniversary of my blog. Basically, I started this whole thing in July 2007 as a travel blog and somehow continued with it through my prospectus and dissertation writing. I'm really happy with how the blog has turned out and am grateful for your thoughtful comments.

I should point out that I fully intend to continue blogging at my usual pace once I achieve an optimal work-sleep-eat equilibrium here in med school! In the meantime, please bear with me and continue to check this space from time to time for new content.

Thank you again for your readership and support. It's been a fun two years and I look forward to more.

Links: Problems with American Health Care, Job Loss and Unhealthy Behaviors

2009-07-12T21:21:00.000-04:00

1. A really interesting piece in the NYT about inefficiency in American health care. The piece, by David Leonhardt, uses prostate cancer as a lens to highlight the gaps between clinical practice and the existing research evidence (or lack thereof). Pretty eye opening stuff.

2. More on American health care: a great piece from The Economist about the challenges awaiting health care reform.

3. My colleagues at Yale, Padmaja Ayyagari, Bill Gallo, Jason Fletcher and Jody Sindelar, along with Partha Deb from CUNY Hunter, have an interesting new paper looking at how job loss influences subsequent unhealthy behaviors. Aside from the interesting research question, this paper is pretty interesting from a methodological standpoint in that they use plausibly (more) exogenous in job loss by exploiting information on business closings as well as employ finite mixture models to model the underlying heterogeneity in effects and people's propensity for unhealthy behaviors. The latter technique is becoming quite hot in health economics now as there is increasing interest in trying to understand how individuals may differ in their underlying propensities towards different behaviors and disease.

Access to Neonatal Care and Cognition

2009-06-27T10:03:00.000-04:00

Ken Chay, Jonathan Gurvan and Bhaskar Mazumdar have an interesting working paper looking at the impacts of improved access to health care during infancy and cognitive test scores. The paper follows black cohorts born before and after desegregation of hospitals in the 1960s and tracks their performance on different cognitive test scores. The main result of the paper is that the convergence in black-white test scores can be explained in large part by improve access to health care. As expected, this convergence is greatest in areas which stood to gain most from the Civil Rights Act. This paper is related to an earlier study, which looked at the birth weights of babies born to black mothers before and after desegregation.

The main message of this piece is that early childhood experiences matter and have long-run benefits. While the previous research in this area has tended to look at the impacts of shocks (famines, recessions, droughts, etc), this paper looks at the impacts of an actual policy and is therefore one step closer to policy relevance. I have a forthcoming working paper that takes a similar approach, looking at the long-run impacts of public health investments in Mexico. Like the study discussed here, I, too, find substantial benefits of such interventions. The next step is to quantify these benefits and assess how this affects resource allocation decisions, which is of great interest and utility to policy makers.

Another thing I like about this paper is its attention to the problem of inference. The study is 72 pages long for a reason: establishing causality is difficult, especially with so many things going on during the time the affected cohorts were born. The authors engage in an impressive number of robustness checks and econometric fixes to rule out competing hypothesis. The authors also present many of their results graphically, which helps put everything on the table up front.

I'm almost tempted to print out their paper and use it as a program evaluation reference...

Back to the Clinic

2009-06-21T11:25:00.000-04:00

I will be starting my third year clinical rotations tomorrow. I'm definitely excited for this: I've been away from medical school for a long time and I look forward to getting back into things and, this time, actually interacting with patients and providers.

Starting third year has a few implications for my blog. First, on difficult rotations I would expect my frequency of posting and length per post to decline. I will try my best not to let this happen, using the blog as my econ outlet especially during months where any substantial research is not realistic to undertake. Second, I will probably include more observations about American health care, especially as it relates to my hospital experiences, than I have in the past. This is a change I welcome: part of what will make my third year more interesting than it would have been pre-PhD is that I now see things with a different set of eyes. I also would like to learn more about American health care, and blogging more about these issues is one step towards that end.

In any case, I look forward to updating this space in the coming months and offering new perspectives and comments. I also look forward to your continued readerships and comments.

Height, Life Satisfaction and Taxes

2009-06-20T16:54:00.000-04:00

Angus Deaton and Rakesh Arora, in a recent NBER working paper, show that:

According to the Gallup-Healthways Well-Being Index daily poll of the US population, taller people live better lives, at least on average. They evaluate their lives more favorably, and they are more likely to report a range of positive emotions such as enjoyment and happiness. They are also less likely to report a range of negative experiences, like sadness, and physical pain, though they are more likely to experience stress and anger, and if they are women, to worry. These findings cannot be attributed to different demographic or ethnic characteristics of taller people, but are almost entirely explained by the positive association between height and both income and education, both of which are positively linked to better lives.

Given the correlation between height and life satisfaction, perhaps stature could be the basis for an optimally designed tax? Mankiw and Weinzeirl explore this idea in another working paper:

Should the income tax include a credit for short taxpayers and a surcharge for tall ones? The standard Utilitarian framework for tax analysis answers this question in the affirmative. Moreover, a plausible parameterization using data on height and wages implies a substantial height tax: a tall person earning $50,000 should pay $4,500 more in tax than a short person. One interpretation is that personal attributes correlated with wages should be considered more widely for determining taxes. Alternatively, if policies such as a height tax are rejected, then the standard Utilitarian framework must fail to capture intuitive notions of distributive justice.

Public Goods and Dentists

2009-06-12T23:43:00.001-04:00

A really interesting paper by Katherine Ho and Matthew Neidell looks at how public goods (goods that people cannot be excluded from, and goods for which use by one person does not diminish use for another) impact businesses. Specifically, they look at fluoridation and the dentistry business. In their own words:

In this paper we consider how the dental industry responded to the addition of fluoride to public drinking water. We take advantage of the staggered introduction of fluoridation throughout the country to analyze the changes in numbers of within-county dentists relative to physicians in the years surrounding the change in fluoridation status. We find a significant decrease in the number of dental establishments and an even larger reduction in the number of employees per firm following fluoridation. We also find that fluoridation in neighboring markets was associated with an increase in own-market dental supply, suggesting that dentists responded to the demand shock by moving from fluoridated areas to close-by markets. Further analysis suggests that some dentists may have retrained as specialists rather than moving geographically. Our estimates imply that the 8 percentage point change in exposure to water fluoridation from 1974 to 1992 may have led to the loss of as many as 0.6 percent of dental establishments and 2.1 percent of dental employees, suggesting a substantial net impact of this public good on the dental profession since its inception.

Pretty good stuff. Neidell has used this identification strategy before, but to look at the effects of good teeth on wages.

Politicians and Poverty Reduction

2009-06-05T19:21:00.000-04:00

A long line of work in political science centers around the topic of clientelism, also known as vote buying. The idea is that politicians (the patrons) provide goods, services or benefits to the public or to those not in positions of power in exchange for votes. (Such favors, for example, could involve the allocation of a large development project to a swing-locality or district). There are lots of reasons to be displeased with "vote-buying" but a big one concerns the marginal returns to public expenditure: funds that are allocated for political reasons may not be allocated productively from the standpoint of some other societal goal. For example, if we are interested in poverty reduction, public funds should be allocated to those who are actually poor (yes, I am oversimplifying here!). Obviously, there is no guarantee that funds allocated by a political formula will follow this more technocratic logic.

So are we destined to an equilibrium where the incentives of politicians and the public are not well-aligned? Not so, according to two recent studies which examine the political impacts of conditional cash transfer programs (CCTs), which are schemes that provide cash to poor families who meet certain objectives (i.e., attending monthly check-ups, sending their children to school, etc; see here for a beautifully detailed account of CCTs the world over) and have been shown to have had numerous positive benefits on health, schooling and general circumstances faced by the poor. The first, by Yale political scientist Ana de la O, looks at the impact of the Mexican CCT, Progresa. Progresa was initially rolled out to a randomly selected subset of localities before more universal rollout a year and a half later. De la O uses this variation to show that people randomly exposed to Progresa longer are around 5 percentage points more likely to vote for the incumbent.

In the second study, Marco Manacorda, Ted Miguel and Andrea Vigorito use a regression discontinuity approach to identify the political impacts of Uruguayan CCT PANES. Comparing individuals just on either side of a pre-designated eligibility score (based on a composite of household and individual socioeconomic characteristics), they find that cash transfers lead to a whopping 21-28 percentage point increase in the probability of voting for the incumbent!

What I like about these papers, besides the use of program evaluation methods to identify causal impacts on voting behavior, is that it suggests that there is a better equilibrium out there: politicians can get re-elected on the basis of policies that have demonstrated large and positive effects on human development rather than through doling out public funds in potentially unproductive ways. My hope is that this catches on in other parts of the world...

Some Graduate School Advice

2009-06-04T23:59:00.000-04:00

I just graduated with my PhD a few weeks ago and have been spending some time thinking over my grad school experience. In the coming weeks, I'm sure I have a lot to say about choosing a grad school, a research field, an advisor, etc, but I thought I'd start by talking about the most important things I learned during the journey. Here goes:

(1) Follow all your leads and persevere: The most important piece of advice I've got. Most projects will not go smoothly, either because of lack of data, some weird programming bug, or some other unforeseen difficulty. If you think it's a good project, with your intuition screaming "yes" and you sense that a breakthrough is possible, KEEP GOING. Sometimes you need to hit your head against the wall, over and over, till it breaks down. I was in this position about seven months ago, needing a third paper for my dissertation and not sure if I was going to get it to work in time to graduate by May. I found some interesting preliminary results on the long-run effects of clean water and I decided to go forward, working really hard to get data and program what turned about to be conceptually easy, but difficult in practice. It paid off, and I am hoping to expand this paper over the next year in several ways.

As far as the "following all your leads" part, if you think of an interesting question, find some data (it's usually very cheap!) and spend an hour or two seeing if you can't get some preliminary evidence or "proof of concept." If you do, follow it up: the results may surprise you and might have an interesting project on your hands.

(2) But know when to stop: This applies to two situations. The first is with a project that just won't work out anytime soon. And the second is with a mostly complete project. In both situations, the marginal hour, or tweak here and there, will likely not lead anywhere. In the first case, stop, but always keep it in your mind: you're breakthrough could happen a few years later. In the latter case, send the thing out already!

Of course, while you're in the thick of it it's hard to distinguish between when you should take route (1) or (2) [I've been late to pull the trigger on several occasions!]. I think that's part of what graduate school gives you, an intuition of when things will work and when they won't. Until you get there, the best way to distinguish between (1) and (2) is to outsource the experience and intuition based calls to people who have a comparative advantage in these things: your advisors.

(3) Sell, sell, sell!: This is something I really picked up in the last six months of grad school. How well your paper does or how well your talk is received is really based on (a) whether your intended audience gets what you are saying and (b) how well you couch your work in the larger scheme of things. Basically, people need to understand what you are doing and realize that it is important. The only way to get this is with a nice sales job.

For people in fields that are necessarily interdisciplinary (health economics or health service researchers both fit that bill), you need to be able to communicate to people who look at problems with a different disciplinary lens. I noticed that my talks went a lot better when I cut out the economics jargon and explained things in a more universal language. My writing got better from this, as well.

In motivating talks and papers, it is always important to bring in the larger literature first, show where your study is situated, and, at multiple junctures, point out exactly why your study is important and all the new stuff it adds to our knowledge. Humility is good, I've learned, but too much gets you left behind. (On the same plane, too much boasting is bad, too. Never oversell your paper!)

(4) Get really good at fundamentals: My personal view is that it is a lot easier to learn about different topics than it is to pick up different skills. As such, I think the best investment during your graduate years, especially when you are taking classes, is to invest in skills. In any statistics based field, being a quant jock makes you the cool kid at school: everyone will want to work with you.

This doesn't mean that one shouldn't read up on interesting topics. Far from it (see below)! Just make sure you get the requisite tools.

(5) Always work the margins: Grad school is full of ups and downs. On the research side, you'll go from being uber productive to not so productive and back again. I think its really important to have a strategy of riding out low marginal productivity months. This might be the time that you (a) read a lot (b) write a lot (c) take a vacation. Whatever you do, make sure you do it with relish. At some point you will become productive again and have a storm of ideas. When you do, embrace it and go to town.

Some other nuggets of note:
(6) Keep a notebook or pda with a list and short description of all your ideas: Some of them won't pan out initially, but you might be able to revisit them in the future.

(7) Read the popular press: Two of my working papers have come from taking data to statements and problems outlined in newspaper/magazine articles.

(8) Read the literature, but don't binge on it: Some good advice that I got early in grad school was to know the literature, but don't read so much that it destroys your creativity. If you think of an interesting idea, play with it in your mind and ask yourself how you'd address the research question. Once you do, Google Scholar it and see if its been done. If it has, pat yourself on the back for coming up with an interesting question and do it again if the authors adopted your methodology. If not, go to town.

Easterly/Sachs Debate and Other Links

2009-06-03T22:56:00.000-04:00

1. Bill Easterly and Jeffrey Sachs have a lively back-and-forth going on the Huffington Post about how best to tackle global poverty (see here and click the links for previous posts). The debate is informative and also fun from an entertainment standpoint.

2. Nice post from Steve Levitt about how free-markets and poverty reduction strategies can co-exist.

3. If you're bored or devoid of fun these days, here you go.

Measuring Obesity

2009-05-31T21:51:00.000-04:00

A simple, yet illuminating paper (often the best kind of paper!) on the obesity epidemic and why we need measurements beyond BMI:

There are several ways to measure fatness and obesity, each with its own strengths and weaknesses. The primary measure for tracking the prevalence of obesity has historically been body mass index (BMI). This paper compares long-run trends in the prevalence of obesity when obesity is defined using skinfold thickness instead of body mass index (BMI), using data from the full series of U.S. National Health Examination Surveys. The results indicate that when one uses skinfold thicknesses rather than BMI to define obesity, the rise in the prevalence of obesity is detectable ten to twenty years earlier. This underscores the importance of examining multiple measures of fatness when monitoring or otherwise studying obesity.

Now Online: My Talk on Disability Grants and Adherence to HAART in South Africa

2009-05-27T21:37:00.000-04:00

You can find it here (you'll need RealPlayer or RealAlternative to view it). Here is a description of the study, conducted by myself, Brendan Maughan-Brown (University of Cape Town), Nicoli Nattrass (University of Cape Town) and Jennifer Ruger (Yale) from a previous post.

We are currently working on a new draft of this paper and should have that ready in a week or so. In the meantime, I'd love to hear your comments on how to improve upon this study.

HIV/AIDS and the Erosion of Medical Care

2009-05-25T06:50:00.000-04:00

A new and important paper by Anne Case and Christina Paxson finds the following:

We document the impact of the AIDS crisis on non-AIDS related health services in fourteen sub-Saharan African countries. Using multiple waves of Demographic and Health Surveys (DHS) for each country, we examine antenatal care, birth deliveries, and rates of immunization for children born between 1988 and 2005. We find deterioration in nearly all of these dimensions of health care over this period. The most recent DHS survey for each country collected data on HIV prevalence, which allows us to examine the association between HIV burden and health care. We find that erosion of health services is highly correlated with increases in AIDS prevalence. Regions of countries that have light AIDS burdens have witnessed small or no declines in health care, using the measures noted above, while those regions currently shouldering the heaviest burdens have seen the largest erosion in treatment for pregnant women and children. Using semi-parametric techniques, we can date the beginning of the divergence in health services between high and low HIV regions to the mid-1990s.

Case and Paxson are unable to pin down a mechanism for why this is happening. They suggest it is not driven by an erosion of wealth (though the data they use is somewhat lacking in measures of health beyond asset ownership) or reduced demand for medical care by HIV+ mothers. On the other hand, they cannot rule out adverse impacts of HIV/AIDS on the supply of health care workers and/or the diversion of resources to those with HIV/AIDS, perhaps at the expense of other aspects of medical care. As such, the authors rightly point out that there is more work to be done and that this work needs to be done very soon.

I'll have more to say about this in a forthcoming post.

The Human Development Index

2009-05-22T23:53:00.000-04:00

Justin Wolfers put up an interesting post on the Freakonomics blog today about the Human Development Index (HDI), a summary statistic that combines information on life expectancy, schooling outcomes and income per capita. He cites a post by Andrew Gelman, which makes the claim that the Human Development Index for the 50 U.S. states provides little information above and beyond what state income per capita tells you.

Some thoughts:

1) The HDI was first developed in 1990 as a good faith effort to move beyond income as a measure of development. The idea was to capture other aspects of society and wellness that we might think are important in making people content and happy. The fact that there is little information beyond what a simpler measure of income per capita tells you is discouraging on the one hand, as it might imply that we aren't measuring non-monetary aspects of development well. On the other hand, the finding might suggest that wealth creation brings about the other aspects of development we care about, even if these other aspects are important ends in and of themselves.

2) It is important to ask what the content of the HDI is, how it is calculated, and its utility in informing policy. On this note, I'm a bit surprised that neither Wolfers or Gelman cite a seminal paper by my mentor from Duke, Allen Kelley. Written in 1991, Kelley notes the close correspondence between national income per capita and HDI, but also goes into the sausage factory of how the HDI is constructed (its a bit arbitrary) and what the statistic may or may not be able to tell us. The subtitle of his piece, "handle with care," gives you a good sense of his skepticism. The fact that the same skepticism remains warranted nearly 20 years later is more than a bit disturbing.

3) Finally, the blog fivethirtyeight.com is fantastic: the authors use data and elegant statistics to delve deeper into various political and social issues that are often taken for granted. It was first recommended to me by Joachim Hero, and I am now linking it in the sidebar for your enjoyment.

Links: Obama on Global Health, Kindergarten, and the Indian Marriage Market

2009-05-21T08:23:00.000-04:00

1. Karen Grepin provides a nice discussion on Obama's comprehensive strategy on global health. While you are there, check out her interesting piece on advocacy and neglect in the global health arena.

2. In an interesting new paper, Elizabeth Cascio finds that the introduction of kindergarten programs in the 1960s and 70s led to reduced drop out and institutionalization rates among whites but not blacks. The differential effect, she posits, might have something to do with crowding out federally funded programs helping the poorest black five year olds. I'm not so convinced about this as the mechanism, and I think there is a study waiting to happen that looks at health effects, as well.

3. A fun new paper by Abhijit Banerjee and co-authors looks at the Indian marriage market. From the abstract:

This paper studies the role played by caste, education and other social and economic attributes in arranged marriages among middle-class Indians. We use a unique data set on individuals who placed matrimonial advertisements in a major newspaper, the responses they received, how they ranked them, and the eventual matches. We estimate the preferences for caste, education, beauty, and other attributes. We then compute a set of stable matches, which we compare to the actual matches that we observe in the data. We find the stable matches to be quite similar to the actual matches, suggesting a relatively frictionless marriage market. One of our key empirical findings is that there is a very strong preference for within-caste marriage. However, because both sides of the market share this preference and because the groups are fairly homogeneous in terms of the distribution of other attributes, in equilibrium, the cost of wanting to marry within-caste is low. This allows caste to remain a persistent feature of the Indian marriage market.

Imports and Development

2009-05-20T11:04:00.001-04:00

It's always fun when a friend or colleague of yours is mentioned in The Economist. Last week was no exception, when the venerable periodical covered a recent piece on trade co-authored by Amit Khandelwal, a former Yale economics graduate student now at the Columbia Graduate School of Business as an assistant professor.

The research in question looks at the effects of imports on aspects of economic development. As the Economist piece points out, in policy discussions on trade, there is this belief that exporting is good for the home country's development, but importing is not. Khandelwal et al's piece shows that, in the case of India, imports have had some positive benefits. Quoting from the news article:

As part of those reforms, India slashed tariffs on imports from an average of 90% in 1991 to 30% in 1997. Not surprisingly, imports doubled in value over this period. But the effects on Indian manufacturing were not what the prophets of doom had predicted: output grew by over 50% in that time. And by looking carefully at what was imported and what it was used to make, the researchers found that cheaper and more accessible imports gave a big boost to India’s domestic industrial growth in the 1990s.

This was because the tariff cuts meant more than Indian consumers being able to satisfy their cravings for imported chocolate (though they did that, too). It gave Indian manufacturers access to a variety of intermediate and capital goods which had earlier been too expensive. The rise in imports of intermediate goods was much higher, at 227%, than the 90% growth in consumer-goods imports in the 13 years to 2000.

Good stuff.

Antidepressants and Suicide

2009-05-09T11:17:00.000-04:00

Whether antidepressant use increase suicide risk in the short-term is an ongoing debate in the clinical medicine and health policy worlds. A few years back, based on some evidence that antidepressant use was correlated with a higher risk of suicide, the FDA issued a "black box" warning, forcing manufacturers to acknowledge the increased risks on packaging and materials related to the drugs. The public responded predictably: antidepressant use dropped notably after the warning. (See this 2006 article for more on the issue)

The biomedical model that links antidepressant use to suicide is the following. Depressive symptoms involve both mood and reduced activity. Antidepressants, it is thought, start working by increasing activation before mood. As a result, the hypothesis is that, in the short term, people who have suicidal thoughts may actually carry it out because they are now "activated."

But is there another explanation that could explain the link between anti-depressants and suicide? An important possibility is selection: anti-depressants are taken by people with depressive symptoms, who are more likely to commit suicide. The fact that the association between anti-depressant use and suicide only exists in the short-run could be explained by this selection model as well: those who would commit suicide would do so, and those who are left may have been unlikely to do so in the first place or were prevented from doing so by the medication.

The overall literature on anti-depressants and suicide gives some support to the selection hypothesis. First off, the relationship between use and suicide seems to vary from study to study and across countries. We would not expect this if the biological model were correct. Second, the "black box" warning provides an interesting time series test. In several countries, the use of anti-depressants dropped after the public was informed about the potential risks, and the incidence of suicides actually increased. This runs counter to what we would expect from the biological mechanism model.

A recent paper (forthcoming in the Journal of Health Economics) provides what I think is the most careful analysis of the causal relationship between anti-depressant use and suicide, taking explicitly into account the potential selection bias issue. The authors, Jens Ludwig, Dave Marcotte and Karen Norberg, utilize an instrumental variables (IV) approach:

In this paper we present what we believe to be the first estimates for the effects of SSRIs on suicide using both a plausibly exogenous source of identifying variation and adequate statistical power to detect effects on mortality that are much smaller than anything that could be detected from randomized trials. We construct a panel dataset with suicide rates and SSRI sales per capita for 26 countries for up to 25 years. Since SSRI sales may be endogenous, we exploit institutional differences across countries that affect how they regulate, price, distribute and use prescription drugs in general (Berndt et al., 2007). Since we do not have direct measures for these institutional characteristics for all countries, we use data on drug diffusion rates as a proxy. We show that sales growth for SSRIs is strongly related to the rate of sales growth of the other major new drugs that were introduced in the 1980s for the treatment of non-psychiatric health conditions. This source of variation in SSRI sales helps overcome the problem of reverse causation and many of the most obvious omitted-variables concerns with past studies. Our research design may also have broader applications for the study of how other drug classes affect different health outcomes.

Using this strategy, they find that a 12% increase in anti-depressant sales is associated with a 5% decrease in suicides. Interesting stuff.

While the main innovation in the paper is the use of instrumental variables, this may also the main weakness. First, as discussed in previous posts, in order for the IV approach to work, the instruments should only affect the outcome through the exposure of interest. The authors in this paper go through some trouble to establish the validity of their IVs. Its all carefully done and compelling, but, depending on your priors about institutional differences in pricing strategies, you may still have qualms about the IV.

The other issue with IVs, is that the effect it computes applies to those people (or here, groups of people) that are most affected or sensitive by the instrument (see this earlier post for more on this). Thus, it is very important to note that the finding in this paper does not rule out the possibility that anti-depressant use might have adverse impacts on some populations. I think this is of particular interest to clinicians, and there are new methods in econometrics that can help uncover heterogeneity in treatment effects (see this paper on the heterogeneous impacts of treatment on breast cancer, utilizing methods developed by Heckman and co-authors).

Staying Off Facebook with Help from Behavioral Economics

2009-05-05T17:56:00.000-04:00

A few days ago, I got pretty annoyed with some stuff on Facebook and wanted to stay away from it for a while. Unfortunately, logging into Facebook is too easy. Actually, somehow I'm always signed on on my laptop and blackberry. That, coupled with the fact that I addictively check my newsfeed and spend a lot of time in front of my computer, made it difficult to stay off of the site for long.

So, I decided to take a more "drastic" step: deactivation. While I guess you can never really leave Facebook, you can take your profile offline. Deactivation means that others cannot find you, message you or whatever.

Since I've deactivated, I haven't been on Facebook for a couple days and things are just great. But, at first blush, it might be a mystery to some as to why deactivation would work. After all, to reactivate, I'd just have to log back into the website (yeah, it's just that easy). So how could this have any effect on my Facebook behavior? I think there are a few reasons:

(1) I like marginal costs that are essentially zero. Deactivation raises the marginal cost of going on Facebook just a little bit, which might work to totally devalue what in my head should be a free experience (see here for a good discussion of this phenomenon in another context).

(2) Deactivation works for me as a self/pre-commitment device (see here for a broader discussion). I realized I'd feel a lot worse repeatedly deactivating and reactivating rather than just navigating from Facebook to another page and back. In the former case, I'd feel like more of a flake or diva for signing off a service and going back on, whereas that kind of behavior is more easily justified when you are already part of the service.

So behavioral economics has helped me get around my Facebook conundrum. Interestingly, various behavioral economics inspired "nudges" almost stopped me from establishing my pre-commitment device. When you go to deactivate, you are shown pictures of your five of your friends (from your jointly tagged pictures) with captions like "Mike will miss you," all below the question "Are you sure you want to deactivate?" Furthermore, below the pictures, you are asked to provide a reason for why you want to deactivate, and for all of the choices except "This is temporary. I'll be back" Facebook gives you a pithy statement about why you might want to reconsider.

Finally, see you on Facebook...at some point in the future.

The Cost of Political Opposition

2009-05-04T20:08:00.000-04:00

Dissent is an important part of public discourse in any setting. In a truly democratic regime, one would expect dissent to carry little cost (though I expect it might in hard to observe ways). But what about in autocratic regimes? What is the price of opposing the ruling party?

In a recent working paper, Chang-Tai Hsieh, Edward Miguel, Daniel Ortega and Francisco Rodriguez try to address this question in the context of the Hugo Chavez led Venezuela. In their own words:

In 2004, the Chávez regime in Venezuela distributed the list of several million voters whom had attempted to remove him from office throughout the government bureaucracy, allegedly to identify and punish these voters. We match the list of petition signers distributed by the government to household survey respondents to measure the economic effects of being identified as a Chavez political opponent. We find that voters who were identified as Chavez opponents experienced a 5 percent drop in earnings and a 1.5 percentage point drop in employment rates after the voter list was released. A back-of-the-envelope calculation suggests that the loss aggregate TFP from the misallocation of workers across jobs was substantial, on the order of 3 percent of GDP.

That political opposition in an autocratic regime can invite economic retribution is not that surprising, but the 3% of GDP number kind of is. It's just a great illustration of how the incentives of the public and autocratic leaders are not aligned: one would hope that a 3% loss of GDP would have dissuaded Chavez from going after his opposition.

All in all, a really interesting, if not very sad, read.

(Ed: Marginal Revolution has an interesting take on this paper, as well)

Shaan's Blog and Swine Flu

2009-04-29T11:57:00.001-04:00

My friend, former tennis partner and former Yale MPHer Shaan Chatturvedi has just started blogging about his experiences in Guyana, where he is currently a working for the CDC Global AIDS Program. His most recent post, on the swine flu outbreak, is fantastic and promises of good things to come from his blog. Do check it out!

For more on the swine flu, check out this interesting article by Dr. Carlos del Rio, the chair of the Global Health Department of the Emory School of Public Health. There is a lot of interesting stuff in there about different control measures and the reasons why swine flu mortality might be higher in Mexico than in the US.

Long-Run and Intergenerational Effects of Early Childhood Environments

2009-04-21T11:15:00.000-04:00

Great NBER working paper this week on the long-run and next generation returns to early life conditions. Specifically, Eric Gould and co-authors look at consequences driven by the airlift of Yemenite immigrants into Israel. In their own words:

This paper estimates the effect of the childhood environment on a large array of social and economic outcomes lasting almost 60 years, for both the affected cohorts and for their children. To do this, we exploit a natural experiment provided by the 1949 Magic Carpet operation, where over 50,000 Yemenite immigrants were airlifted to Israel. The Yemenites, who lacked any formal schooling or knowledge of a western-style culture or bureaucracy, believed that they were being "redeemed," and put their trust in the Israeli authorities to make decisions about where they should go and what they should do. As a result, they were scattered across the country in essentially a random fashion, and as we show, the environmental conditions faced by immigrant children were not correlated with other factors that affected the long-term outcomes of individuals. We construct three summary measures of the childhood environment: 1) whether the home had running water, sanitation and electricity; 2) whether the locality of residence was in an urban environment with a good economic infrastructure; and 3) whether the locality of residence was a Yemenite enclave. We find that children who were placed in a good environment (a home with good sanitary conditions, in a city, and outside of an ethnic enclave) were more likely to achieve positive long-term outcomes. They were more likely to obtain higher education, marry at an older age, have fewer children, work at age 55, be more assimilated into Israeli society, be less religious, and have more worldly tastes in music and food. These effects are much more pronounced for women than for men. We find weaker and somewhat mixed effects on health outcomes, and no effect on political views. We do find an effect on the next generation – children who lived in a better environment grew up to have children who achieved higher educational attainment.

I find this paper noteworthy for several reasons:

(1) The authors have a credible and interesting source of variation, and the actual early life exposures they look at have immediate policy implications

(2) The authors explore a wide variety of different outcomes, including behavioral aspects. In my dissertation, I argued that long-run returns need to be taken into account when making resource allocation decisions. However, this is difficult if only a subset of long-run returns are known. This paper really hits this gap.

(3) Finally, and more self-serving, the long-run effects of sanitation and clean water jive well with my thesis paper on the National Clean Water Program in Mexico (see the next post).

Correlation Does Not Imply Causation. And...?

2009-04-03T11:25:00.000-04:00

Since I started grad school four years ago, I've noticed that the general public is much more attuned to idea of correlation not always implying causation. Of course, the indoctrination is not complete just yet, and there are plenty of instances where an association is mistaken for something more, but the fact that people are becoming better consumers of statistics is gratifying. I attribute this to the spate of popular press economics and statistics books/blogs in the last few years (though I might be in danger of confusing correlation and causation myself by saying this!)

The standards in empirical research reflect how seriously people are taking this motto: finding a clever instrumental variable or even experimental variation is no longer good enough. Papers without extensive "robustness" checks and falsification tests have less credibility now than they would have even five years ago. This, like the trend in the general public, is a good development.

However, with these positives come some more troubling tendencies. Specifically, I have a beef with the overuse of the causation-correlation dictum. Now, anybody can bring down a paper simply by saying "correlation does not imply causation" without having to provide a reason why this might be the case. For example, I am working on a paper looking at the long-run causal effects of birth year exposure to a clean water and sanitation efforts (I'll post a link to this paper in a month or so when a good draft is ready). I have a plausible identification strategy, and also include all sorts of controls, trends and falsification checks in my analysis to further establish causality. My results check out.

However, someone recently remarked told me that I should be concerned about omitted variables. When I pressed her on what these might be, she wasn't sure but commented that "there are always omitted factors."

Clearly, this isn't helpful. It's really easy to look/sound clever and point out that correlation does not imply causation: it is technically a true statement! But I think people who make this claim should talk about how it applies to the analysis at hand (i.e., have some kind of model or story that makes more explicit the nature of the potential biases and where they come from). Otherwise, the statement by itself is pretty uninformative and does little to advance our knowledge.

Peer Effects in Technology Adoption and Consumer Decisions and Other Interesting Links

2009-03-30T11:11:00.000-04:00

1. Emily Oster and Rebecca Thorton have an interesting new paper that uses individual-level randomization to understand, among other things, how peers affect a woman's decision to utilize newly introduced menstrual cups in Nepal.

2. Enrico Moretti looks at the importance of social learning from peers in consumption decisions - particularly the decision to see different movies. I really like this paper: Moretti starts with a theoretical model and uses the uniqueness of the film industry to test it. It's great stuff. And he goes on to find that social learning is non-trivial:

Overall, social learning appears to be an important determinant of sales in the movie industry, accounting for 32% of sales for the typical movie with positive surprise. This implies the existence of a large “social multiplier” such that the elasticity of aggregate demand to movie quality is larger than the elasticity of individual demand to movie quality.

3. Behavioral economics strikes again! Apparently a good way to save money is to carry around Benjamins over Abes and Georges.

4. The Economist is right on about the decision to move the Indian Premier League cricket matches to South Africa because of the upcoming election in India. What kind of aspiring superpower justifies moving a thriving capitalist enterprise by claiming that they cannot guarantee the safety of the players and spectators? Isn't this exactly what terrorists want to happen?

Is the Row Over AIG Bonuses Getting Ridiculous?

2009-03-26T08:42:00.000-04:00

Yes.

Certainly, handing out a bonus package running in the hundreds of millions of dollars during a recession seems like poor form. Especially so when the firm involved played a big role in bringing the house of cards down. However, the public vitriol over this mess has taken on a disturbing character.

A recent open resignation letter by a former AIG VP printed in the New York Times does a pretty good job of laying out the argument. Basically:

(1) Salaries at AIG are low and most people make money through bonuses.
(2) The people responsible for the failure of AIG are no longer working there. The contended bonuses weren't meant to be given out to people in unrelated divisions doing unrelated things.
(3) The bonuses were part of a contractual obligation to get good workers to stay on during tough times. But more fundamentally, the bonuses were part of a compensation package promised to employees before AIG became the demon.

My beef with the whole row hinges on (3). It's ridiculous for people to demand the bonuses to be paid back (or to try and tax these at the rate of 90% or something like this). Nobody should be able to meddle with contracts retroactively. This is because this kind of activity could discourage people from generating real wealth during these tough times: why would anyone try to make money in this climate if they believe they are going to be demonized and that the government will try to take their money away. The bonuses row could serve as a huge disincentive for undertaking the kind of economic activities that we desperately need now.

Reason (2) also deserves some attention. While I don't see it as the best argument against the retroactive penalities (the whole company as a team argument), we need to think about how a few people could derail an entire financial system despite being around a majority of people who were engaged in activities that ostensibly generated real wealth. Perhaps the Geithner regulatory plan, to be announced sometime soon, will address this in a constructive way that doesn't hamper wealth creation.

Whatever the case may be, it is time to put down the pitchforks and start thinking about these issues in a more constructive (and less obviously destructive) manner.

Experiments, Natural Experiments and Learning about Development Policy - I

2009-03-18T20:33:00.000-04:00

A while back I blogged about the Jameel Poverty Action Lab, a non-profit organization started and run by economists carrying out randomized field experiments all over the developing world. The purpose of these experiments is to build an evidence base to inform policy-making, and randomization as a tool towards this end has become quite popular of late. Proponents of randomization, now called "randomistas", argue that, as with medical clinical trials, field experiments are the "gold standard" in development policy evaluation.

But is this really so? In two recent pieces, Angus Deaton and Martin Ravallion argue that the answer is "no." One of their main arguments centers around the idea of heterogeneity in treatment effects, which basically refers to how policies do not have the same impacts for everyone. Consider an example where we are thinking about implementing some large policy and want to learn whether it might be effective. To do so, we consult data from a recent experiment in which some individuals in the sample have been randomized to receive "treatment." We then compare the treatment and control group outcomes.

Randomization of individuals to treatment gives us confidence that the results of the experiments are not biased. However, the concern is whether one can learn something useful about the policy from this experiment. In most field experiments, individuals in the treatment group are either enrolled in a program or incentivized to participate in some way. In most cases, not everyone complies, and some groups of individuals tend to be more likely to comply than others.

The important thing to note is that the program effects that are recovered from the experiment is most reflective of the returns to the group of compliers. This is referred to as a "local average treatment effect", or LATE. Here is where the problem comes in: the LATE that an experiment recovers may not always be policy relevant and, unlike the issue of limited external validity (experimental results in one setting may not apply to others), it is not clear that replications will help get around this problem. To reiterate, the benefits of the program that infer from an experiment may or may not be informative about this program on a larger scale.

Ultimately, this is problem of experiments being "atheoretical." That is, simply looking at experimental averages is not enough: we have to understand who in the treatment group actually responds to the randomization and takes up treatment and whether this group is of interest to the broader policy picture. Building this understanding brings us back to economic theory: we need a model. In this sense, the argument goes, proponents of randomization who argue that field experiments are "easy" by obviating the need for models or (strong) assumptions are badly mistaken.

I find this argument compelling. Indeed, there is a parallel literature in the "natural experiments" world that makes similar points. Ultimately, policy design and resource allocation decisions require a great deal of information, only some of which we can get from randomized experiments. Experiments that incorporate theory and heterogeneity, Deaton argues, will be good step towards making the method more useful towards policy decisions. In the next post, I will list a few examples of experimental and quasi-experimental studies that take an approach more grounded in theory.

Private Equity Firms, Orange Juice, and Other Interesting Links

2009-03-03T00:26:00.000-05:00

1. Private equity firms spent much of the last decade throwing around large sums of money buying out companies and selling them out for profit after a series of adjustments. The high profile nature of these buyouts and the sheer amount of capital being thrown around begs the following question: what is/was it all for? In a recent working paper, Philip Leslie and Paul Oyer ask whether private equity firms "create value." Their results depressingly suggest than the answer is "no."

2. Steven Levitt has a great post on the intersection between orange juice, environmentalism, and behavioral economics.

3. Will the financial downturn mean less US money for global health? Karen Grepin reports that these outlays are safe for now.

4. Bouts of occasional stupidity are apparently very good for your development as a researcher (summary of the article here). I have yet to see any returns from this. (HT: Melanie Elliot)

Kenya to Deworm, Female Bank Robbers and Other Random Links

2009-02-26T23:04:00.001-05:00

I'm in full-scale dissertation writing mode, so all you're getting from me between now and March 16th are links (if that). Enjoy!

1. Kenya has decided to roll-out a nationwide, school-based deworming program. The impetus for this likely came from some now famous experimental research carried out by Poverty Action Lab researchers Edward Miguel and Michael Kremer, showing that deworming (a) has large effects on school attendance and that these impacts are underestimated if one doesn't account for externalities (i.e., worms are infectious) and (b) is a highly cost effective way to improve schooling.

2. Martin Anderson, a former Yale MPHer and now a PhD student in Health Economics at Harvard, has started writing for the Social Science Statistics Blog (linked in the sidebar). His first post, on Medicaid drug procurement and the market for pharmaceuticals, is awesome.

3. Will tax credits stimulate the economy? Evidence from 2008 suggests not.

4. The number or share of bank robberies committed by women: a new leading or coincident indicator?

Rising Incomes and Health Care Expenditures

2009-02-20T10:19:00.000-05:00

We all know that health care expenditures as a percentage of GDP (per capita) has increased greatly over the last few decades and that this phenomenon has been observed in the US and foreign countries alike. Recent research has tried to understand the determinants of this increase and one common explanation is that health care is a luxury good: that is, as incomes rise people demand more and more of it. In some sense, this might make rising health care expenditures less ominous: we spend more only because it is an expression of our preferences.

Empirical evidence linking incomes to health generally supports the luxury good hypothesis and is based on establishing correlations between the two in micro and aggregate data. However, in a recent working paper, Daron Acemoglu, Amy Finkelstein, and Matthew Notowidigdo argue that this evidence may be misleading for two reasons. First, simple correlations do not capture other unobserved factors associated with income that might affect health. Second, such models do not distinguish between/account for partial and general equilibrium effects: for example, rising demand for health care generated by income may increase spending both through increased local demand, but also through supply side changes in medical technology or practices that respond to changes in demand. In addition, rising incomes and demand may lead to changes in the politics around health care and health services. In either case, it is important to understand both partial and general equilibrium t truly characterize the relationship between income and health.

Acemoglu, Finkelstein and Notowidigo try to get around both of these issues by utilizing shocks to oil prices. The basic idea of their paper is the following:

1) Look at a bunch of smaller areas which may or may not have pre-existing oil industries.
2) Changes in world oil prices, which are not driven by small industry in any single area will affect localities with oil industries differently than those without them. Thus, these two types of areas will experience different "shocks" to income. (Thus, the effect of income on health care demand is identified by the interaction between pre-existing oil industries and world oil price shocks). The next step is to look at the association between predicted income from oil price shocks and measures of health care demand.
3) Establish that general equilibrium effects occur at the level of localities and that it is unlikely that changes in local demand have equilibrium effects on larger regions (such as nations or the world).

The authors findings strongly suggest that health care is NOT a luxury good and that rising incomes likely cannot explain an important portion of the rise in health care expenditures.

Neat paper on an interesting area of research, and definitely worth reading.

Financial Crisis Trickling Down...

2009-02-13T20:14:00.001-05:00

Time Magazine recently put out a piece identifying "25 People to Blame for the Financial Crisis." Actually, their piece should be retitled "300 Million People to Blame..." because one of the parties they accuse is the set of American consumers. The charge? Living beyond their means.

On this note, I've noticed recently that everyone is taking small steps to try and survive the downturn, sometimes in the most unexpected places/ways. Consider what happened to me yesterday:

1) I was told that I would have to provide my own cake for my upcoming thesis defense because the Graduate School was no longer making such purchases.

2) I was kicked out of Au Bon Pain because the management wanted to close up shop an hour early. One of the employees told me that the reason for this was that the cost of paying him for the extra hour and using the electricity far exceeded anything they would get from additional business. He went on to mention that, recently, the store would close early if number of customers was low, and urged me to bring my friends to ABP as well as to the nearby also suffering Gourmet Heaven.

Will the forthcoming tax breaks/credits and wages paid out to the labor force soaked up in infrastructure related jobs induce us to stimulate the economy by spending more money at ABP or on cakes? Only time will tell. At present though, the difference between our habits last year this time and our actions now are striking. I wonder if our new found parsimony will persist even after the crisis weathers: some recent research by Ulrike Malmendier and Stefan Nagel (see here for a summary) has shown that recession/depression era cohorts do have different investment habits (those experiencing macroeconomic hardship at young ages tend to be less risky and are less likely to participate in the stock market). Perhaps this extends to savings and spending behaviors, as well. Thoughts?

Prospects for the Stimulus Package and Other Links

2009-02-12T00:06:00.001-05:00

1. I lot of people have asked me what I think about the stimulus package and I have no idea what to tell them. Bigwig economists are of little help, as well: everyone has a different view on whether this thing will work or not. Some recent pieces in The Economist's Voice illustrate the diversity of opinions on the plan. All well written and worth checking out.

2. I'm sure by now you've heard about PETA's banned Super Bowl ad, which unabashedly claims that "vegetarians have better sex." Justin Wolfers at Freakonomics checks this contention out in the data, providing an interesting discussion on the whole correlation vs. causation angle to boot (it's not what you think).

3. The link between vaccines and autism (which has some frighteningly strident supporters) always seemed a bit dodgy to me. Turns out that at least parts of the original Lancet article this whole movement was based on may have been falsified. A good lesson on responsible science: said paper precipitated a drop in MMR vaccination coverage from over 90% to just 80% in Britain. It's worth being careful in publishing results that will induce people to do potentially unwise things based on tenuous evidence.

"Dakar to Port Loko"

2009-02-09T14:55:00.000-05:00

I recently went to a screening of Yale political science graduate student Nathaniel Cogley's extremely well-done and worthwhile documentary "Dakar to Port Loko: Perspectives from West Africa". I highly recommend this film. Nathaniel spent a few years in West Africa after college, camcorder in tow, with his goal being to "let Africans speak for themselves." And, boy, do they: the film covers everything from opinions on US international policy, to civil war, to microcredit. It's eye opening stuff all around.

Chris Blattman with more about the film and Nathaniel's very interesting background (as well as video of the film's trailer).

Risky Behaviors and HIV

2009-02-06T09:01:00.000-05:00

An interesting paper by Pascaline Dupas looks at information provision and their impacts on HIV-related risk behaviors among youngsters and has something to say about what works and what doesn't (here is a non-gated version):

I use a randomized experiment to test whether information can change sexual behavior among teenagers in Kenya. Providing information on the relative risk of HIV infection by partner's age led to a 28% decrease in teen pregnancy, an objective proxy for the incidence of unprotected sex. Self-reported sexual behavior data suggests substitution away from older (riskier) partners and towards protected sex with same-age partners. In contrast, the national abstinence-only HIV education curriculum had no impact on teen pregnancy. These results suggest that teenagers are responsive to risk information but their sexual behavior is more elastic on the intensive than on the extensive margin.

That information might be more useful in making existing behaviors less risky but not eliminating them altogether was a point critics of PEPFAR made most vociferously. Indeed, this is a finding that is probably in line with most people's priors.

Workshops at Yale's StatLab

2009-02-05T15:04:00.000-05:00

Here is the schedule for statistical package workshops offered through Yale's StatLab for Spring 2009. On the bill are workshops for HTML, Stata, SPSS and R, as well as tutorials on data management and survey data. I highly recommend these workshops for anyone interested in doing empirical work. I took the beginner Stata and R workshops during my first year of graduate school and both served as a great platform upon which to play around and add new knowledge.

There are some excellent web-based tutorials for statistical packages as well. My favorite is the UCLA Academic Technology Services Statistical Computing page, which offers a plethora of links (including pages for Stata, SAS, SPSS, and R).

Interesting Global Health Blogs

2009-02-05T08:28:00.000-05:00

I recently came across two interesting blogs on global health. The first is by Karen Grepin, a PhD candidate at Harvard, and the second is out of MIT. Both blogs are more policy oriented and deal with hot issues in global health - spending, funding, disease outbreaks, etc - about which I somehow seem to know little (despite me being interested in, among other things, "international health"). You'll find both spaced linked in the sidebar from now on.

Dissertation Teaser

2009-02-02T23:15:00.000-05:00

Here are the first few bars of my dissertation's introduction. (I'm planning to submit the thesis by March 16):

There are wide disparities in health and socioeconomic outcomes both within and across countries. Recent work in economics and epidemiology suggests that differences in conditions faced by individuals very early in their lives may help explain a substantive portion of these gaps. In particular, exposure to a variety of shocks and investments in utero and in early childhood is strongly associated with differences in morbidity and mortality risk, cognition, and socioeconomic status over the rest of the life cycle. There is evidence that the effects of these shocks extend across generations, as well. Work from the biomedical sciences suggests that these long-run and intergenerational impacts may be driven by complex biological processes, where early life environmental conditions induce adaptive changes in gene expression and physiological processes that persist into adulthood. While such changes may allow individuals to survive environmental insults in the short run, they may be deleterious to health, mental capacity and productivity in the longer-run.

The literature on the persistence of early life conditions has grown considerably in the last decade. However, many important questions remain unanswered and warrant research attention. First, the policy implications of much of the literature on early life shocks are not obvious. While studies of the long-run effects of events such as famines, droughts, pandemics, recessions and other plausibly exogenous shocks allow for more confidence in inferring causality, their results do not readily suggest appropriate directions for policy intervention. Second, outside of evidence from animal studies, little is known about the mechanisms underlying these long-run effects, particularly in the context of intergenerational impacts and cross-generational correlations in health, more broadly. Finally, there is little consensus on the extent to which disparities in early life conditions can account for the gaps in health, human capital and economic status at various points in the life course and the extent to which such impacts can modulated by investments and conditions faced later in life. This dissertation attempts to address these gaps in the literature and primarily focuses on developing countries, for which evidence on the long-run effects of early life conditions is relatively scant.

"Slumdog" Child Actors: Part III

2009-01-29T16:54:00.000-05:00

This just in from Entertainment Weekly:

Back in November, when Slumdog Millionaire was just starting to heat up, I interviewed director Danny Boyle for a feature in Entertainment Weekly. At one point, we chatted about the challenge of hiring and directing three small local children who spoke only Hindi. One, Ayush Mahesh Khedekar (who plays the youngest Jamal), comes from a middle-class background, while the other two, Rubina Ali and Azharuddin Ismail (who play the youngest Latika and Salim), are from Mumbai slums similar to those depicted in the film. Boyle mentioned that he and the producers, cognizant of how a movie like Slumdog could change the kids’ lives for the worse if proper care wasn’t taken, had set up a trust fund for Ali and Ismail, accessible only if they enrolled in school -- a first for both of them. “They’d never been to school,” Boyle said. “So they have to stay in school until they’re 18. When they reach 18, and if they’ve passed all their exams, a quite substantial sum of money -- extra money [on top of their salaries] -- will be released to them.”

Boyle wasn’t presenting this in a Look at what a good, moral Westerner I am! See how I take care of the less fortunate! kind of way. Rather, he was explaining a course of action that, to me, seemed logical, responsible, and just. But now, an article printed in Britain's The Telegraph earlier this week has stained those good intentions with accusations of exploitation. In the story, Ali and Ismail’s parents accuse Boyle and producer Christian Colson of stiffing their kids out of a decent wage, alleging that their payment for a year’s work was “less than many Indian domestic servants.” This article comes on the heels of earlier reports that many Indians are taking offense with the title of the movie. Consider the flames of the inevitable Slumdog backlash duly fanned.

The movie’s distributor, Fox Searchlight, as well as Boyle and Colson, all have responded to the Telegraph story with statements, asserting that “For 30 days’ work, the children were paid three times the average local annual adult salary,” and that the families have been given funds to cover “basic living costs, health care, and any other emergencies.” A subsequent Reuters news clip shows the father of one of the kids back-pedaling on the accusations, but is it possible the damage is done? The kids’ lives are now disrupted, with camera crews busting into their classrooms. Moreover, concerned that such public talk of money could make Ali, Ismail, and their families a target for local Mumbai criminals, Searchlight has moved them into private housing. For now, it seems this mess isn’t as out of hand as what happened with The Kite Runner kids in 2007, but how does the situation sit with you, PopWathgers? Who, if anyone, is at fault here? The media for stirring up drama? Searchlight? The Parents? And does the controversy affect how you feel about Slumdog?

So the trust fund is indeed a conditional cash transfer, which strikes me as paternalistic (similar to the strategy Dan and Valli discussed in their comments in the last post). At the same time, I like the fact that the children's families basic needs were addressed. Either way, I would have loved to be a fly on the wall during the numerous discussions that must have gone down regarding these payments.

"Slumdog" Child Actors: Part II

2009-01-27T18:18:00.000-05:00

So, as it turns out, Hollywood has taken care of the child actors in Slumdog Millionaire. Quoting a quote from a Freakonomics blog post:

Danny Boyle placed the money to be paid to the three lead child actors in a trust that is to be released to them upon their completion of grade school at 16 years of age. The production company has set up for an autorickshaw driver to take the kids to school every day until they are 16 years old.

Upon their completion of grade school? Is this a conditional cash transfer? Is the reason not to pay to children now because of child labor law or paternalism or both? And have the producers met their obligation, if any, to help these kids out of poverty?

Seriously. I'd love to hear your thoughts.

Is Hollywood Responsible for "Slumdog" Child Actors?

2009-01-24T10:22:00.000-05:00

My sister just sent over an interesting piece about the child actors in "Slumdog Millionaire." As it turns out:

Azharuddin Mohammed Ismail, who plays the youngest version of the main character's brother Salim in the film, lives with his parents and siblings in a makeshift plastic tent, pitched on a half-finished government park.

Besides friends and neighbours, he has a big garbage dump and armies of mosquitoes and flies for company.

Ten-year-old Azharuddin's mother says they have been homeless for a while: "We have been squatting on this government park since the time our hutments were demolished over a year ago and despite showing the right documents to the authorities we have not been allotted our room [a one-room tiny flat]."

Rubina Ali - who portrays the youngest version of the leading lady Latika in the film - is playing with Azhar and other children.

Their faces glow in the rays of the fading sunlight. They greet the BBC team with coyness. Ask them to pronounce the film's title and they fumble amid nervous smiles. "Aslum dog minaire," says Rubina. "No," Azhar tries to correct her, with his own incorrect version.

Here is a question I am pondering: do the producers of "Slumdog Millionaire" have a responsibility to help these child actors out of poverty? Especially when that same poverty was used to entertain millions? I'd like to hear your thoughts.

By the way, you should see "Slumdog Millionaire" - it's excellent.

Health in Post-Communist Economies

2009-01-24T09:05:00.000-05:00

One of the most striking trends in population health over the last two decades has been the rapid fall in life expectancy at birth in Russia and other post-communist economies in the late 80s through the mid1990s. From the late 1990s onwards, the country rebounded, but still has not recovered to the pre-drop values (in fact, the Russian life expectancy in 2007 is still lower than it was in 1970).

A recent article in the Lancet examines the causes of this notable drop using longitudinal sample of Eastern European and former Soviet Bloc countries and suggests that rapid and ill-planned economic-reform (mass privatization), which lead to equally drastic increases in male unemployment rates, could be responsible for the depressing trends in mortality rates (here is a link to the Lancet version and here is a similarly titled and much longer working paper version). The association between rapid privatization and mortality holds even when the authors control for a variety of other correlated factors (prices, trade liberalization, income, etc). The authors also find that the effect of privatization is lower when more people are engaged in the public space (i.e., more "social capital").

This is an interesting and important question and the authors try to address the robustness of their results to addressing a variety of alternate hypotheses (see, especially, the longer working paper version). However, given data constraints, it is likely difficult to control for shocks that may induce the need for a policy change (for example, economic reform was necessitated by changes country specific trends that would lead to drops in the mortality rate anyway) as well as other pre-existing trends. In addition, the findings with social capital are difficult to interpret since interactions with others and participation in public organization may be correlated with other determinants of mortality or the need to introduce reform itself. A piece on the study in this week's Economist raises some of these concerns, as well (though some of the arguments they make do not seem to be that compelling). in any case, I think researchers have cast an interesting light on an important population health topic and the whole line of inquiry deserves further research attention.

I've come across a spate of other recent research on post-communist economies, as well. Some of the authors on the privatization papers have also written about the effect of another set of structural reforms - in particular, meeting the conditions to receive loans from the International Monetary Fund - on tuberculosis rates. The idea here is that meeting IMF conditionality siphons money from public health and health care to other aspects of the macroeconomy. The findings of this paper suggest that IMF debt and restructuring lead to increases in TB rates in former Soviet Bloc and Eastern European countries, though many of the same concerns I voiced earlier apply to this paper, as well (see especially their meta-analysis of their results - the estimated IMF effect drops as additional controls are added).

Finally, at the American Economic Association conference a few weeks back (more on this in a later post), I saw an interesting presentation on the impacts of parental alcohol use early in childhood on health outcomes later in life (here is a link to the paper). Previous studies on this subject have had difficulty establishing causality, as parental alcohol consumption is a choice and the same tastes and preferences that govern that choice may also influence how they invest in their kids' health. This paper gets around this issue using the discontinuous implementation of a prohibition program. The study thus compares kids born just before the program (and just after) to those born during the program. It also utilizes the fact that prohibition was more strongly enforced in some areas than others.

The author finds strong impacts on health later in adolescence (kids born during probition tend to be taller than their counterparts and report less illnesses). Most interestingly, the prohibition cohort was more likely to receive key vaccinations relative to the controls, suggesting that one mechanism linking parental alcohol use to later health outcomes could be that expenditures on alcohol crowd out expenditure on more productive investments. The biggest threat to validity in this paper is the fact that much of the movement in health outcomes during prohibition appears to be in the areas where the law was less enforced rather than in treatment group.

Summary of Research on Child Development

2009-01-23T10:46:00.001-05:00

Last quarter's NBER Reporter has an excellent summary on recent research on the determinants of child health, education and the impacts of investments and various shocks early in life on later health outcomes. The report, by economist Jonathan Gruber, has plenty of links to recent working papers.

This is a must read for anyone interested in aspects of child development or doing research on the subject. For those outside of economics, the summary offers great insight into what economist are doing and, to a lesser extent, how different econometric tools can be used to address the issue of causality. Possessing theoretical and statistical tools in confronting the latter issue is, in my opinion, a huge comparative advantage that economists have in conducting research in these areas.

Finally, and tangentially related to the topic of child development, the Yale Daily News recently covered the controversy on the importance of peer effects in explaining happiness and obesity. This is really the only news article on this I've read so far that does a good job articulating both sides of the argument.

Random Thursdays

2009-01-22T11:01:00.000-05:00

1. I was excited to see Richard Jenkins get a Best Actor Academy Award nomination for his work in The Visitor. His portrayal of a stuck-in-a-rut development economist who experiences a reawakening through a most unusual and heart-wrenching circumstance was truly one of the best (and least known) performances that I saw all year.

2. However, the Oscars really dropped the ball with some of the Best Picture nominations. The sentimental mess Benjamin Button over the hard-hitting Dark Knight and Gran Torino? Why do these guys get to decide?

3. What is the market value of virginity? See here.

4. The Yale Daily News has a great three-part series on George W. Bush. The first two parts have been pretty interesting so far, portraying the President as far more complex than either liberals or conservatives like to paint him.

Innovation and the NFL

2009-01-13T13:11:00.000-05:00

(Ed: Happy New Year, and sorry for the delay in posting. I will revert to my usual rate of blogging shortly)

I just read a great article about Florida phenom Tim Tebow and his probability of success in the NFL. What was different about this piece than say similar ones about Peyton Manning, Reggie Bush, etc, is the sense that Tebow brings a unique and possibly unprecedented skill set to the NFL that may not have been valued in the past but could have enormous returns as the game evolves.

The piece reminds me of a great book a read a few months ago, The Blind Side: The Evolution of a Game by Michael Lewis. The book chronicles the story of Ole Miss left tackle Michael Oher, who's rise to prominence from a poor, homeless child in and out of school to potential draft day stud was written in the stars years before his birth, with the exogenous introduction of Lawrence Taylor into the NFL. Taylor was such a special player that his rise to prominence raised the returns to having a freakishly gifted athlete guarding a quarterback's "blind side" (i.e., for right handed QBs, it would the left tackle). The increased returns were reflected in the market value of left tackles: NFL wages was artificially depressed until the early 1990s, when the era of free agency lifted the constraints on wages. At this juncture, the wages of left tackles increased precipitously.

I highly recommend The Blind Side, and not just for the economics.

My Favorites from 2008

2008-12-30T14:51:00.000-05:00

(1) Favorite Book - "Three Cups of Tea," chronicling the story of Greg Mortensen, an American mountaineer who, through a series of incredible events, took up the cause of building schools in Northwestern Pakistan and Afganistan, is a great way to close out the year. Mortensen's work (upwards of 70 projects in the region) in education, public health and skill building has probably done more (per dollar or per unit effort) to fight the likely root causes of terrorism - poverty and extremely high opportunity costs to obtaining education and skills - than anything else in recent memory.

A good story to remind us how to go about "going about" next year (and subsequent ones, as well).

(2) Favorite Film - A good hard look at crime, terrorism, civil liberties and how far "good" can go before crossing the line, along with some ridiculously sharp acting by Christian Bale, Heath Ledger and Aaron Eckhart, compels me to put "The Dark Knight" at the top of my film list. Just because the Academy is too stodgy to give "popcorn flicks" Best Picture nominations doesn't mean that this phenomenal movie shouldn't get a nod. (Other favorites: "The Visitor," "Wall-E," "Slumdog Millionaire," and "Milk").

(By the way, "Least Favorite Trailer of 2008" goes to the one for the forthcoming Meryl Streep film "Doubt." Not only was it bizarre the first time around, I've been exposed to it before every movie I've seen in the last six months. Do they ever plan on releasing this film, or is the strategy to just keep showing the preview over and over for some extended period of time?)

(3) Favorite Academic Discourse - Is happiness contagious? James Fowler and Nicholas Christakis argue that it is: you will be happier if you have happier friends, or if your friends have friends who have happy friends. Fowler and Christakis have also argued in the past that obesity and smoking are contagious, as well.

In the same issue of the BMJ containing the happiness piece, Ethan Cohen-Cole and Jason Fletcher (the latter of Yale University) argue that Fowler and Christakis' methodology to examine peer or social-network effects is faulty in that they do not fully control for the common environment shared by all the individuals in the network (after all, you and your friends may be happy because all of you were exposed to a city-wide balloon race or something like this). Using the Fowler-Christakis setup, they are able to show that things that shouldn't be contagious - acne, height and headaches - appear to be susceptible to peer effects just like happiness. When fully controlling for the common environment, these spurious causal effects disappear. (Yup, "Favorite Falsification Test of 2008").

Guess which piece got all the press attention. Justin Wolfers at Freakonomics has a good commentary on the discourse and the manner in which it was reported.

(4) Favorite Post - I really had a good time writing this one.

(5) Favorite Historic Moment - That Obama guy winning.

And, finally, best wishes for the New Year! I'll see you in 2009.

Harvey Milk Documentary on Hulu

2008-12-29T16:54:00.001-05:00

I just found out that you can watch the documentary, "The Times of Harvey Milk" on hulu.com. Here is a link to the film.

I recently saw "Milk," starring Sean Penn, and found it to be extremely interesting, inspiring and ridiculously well acted. After watching the film, I was told by a few people that I might have gotten more out of the Penn version by watching the aforementioned documentary first. Regardless of what you choose to do, you should definitely see the film and check out the documentary.

Cell Phone Free

2008-12-29T14:20:00.000-05:00

Last week, I decided to treat myself to a smartphone and ordered a Blackberry Storm. While my new unit was being activated and sent over, the SIM card on my older phone was deactivated. As I haven't yet received the Blackberry, I have been cell phone-less for the last five days or so.

Not having a phone has been an interesting experience. Some thoughts:

(1) I am much more productive now with work: I need to get a draft of my third dissertation paper done by the first week of Jan (check back in over the next few days for a summary of this work), and I've made more progress in the last week or so than over the previous four weeks.

(2) My social life has taken a tremendous hit: I sent out an e-mail to some friends and family giving them my home phone number. In spite of me being an excellent conversationalist, nobody has called my alternate number. I attribute this to the fact that having a cell phone diminishes the returns to memorizing phone numbers to zero. As such, the fixed cost of learning a new number or entering into your address book becomes high enough for people to wait until your old number comes back online to call. At least, this is what I am telling myself.

(3) My risk of getting cancer has probably remained constant: There is a growing and very controversial body of work on whether cell phone use (or exposure to mobile towers) increases ones risk of getting various tumors. Most of these studies suffer from omitted variables bias and the fact that cell phone use being widespread only for 10-15 years or so, the follow up period is just not long enough to make many of the purported positive results to actually be plausible.

(4) My risk of getting in a car accident may not have changed, either: This one is based on a really clever piece of research by Saurabh Bhargava and Vikram Pathania trying to get at the causal effects of cell phone use of traffic accidents. From their abstract:

Previous research in the laboratory and by epidemiologists has compared the danger of cell phone use while driving to that of illicit levels of alcohol. This paper investigates the causal link between driver cell phone use and crash rates by exploiting a natural experiment - the discontinuity in marginal pricing at 9pm on weekdays when cellular plans transition from peak to off-peak pricing. We first document that this pricing threshold induces a 20 to 30% jump in call volume for two samples of callers. We then document the corresponding change in the fatal and all crash rate. Using the years prior to the introduction of two-tier pricing as a control, as well as weekends as a second control, we find no evidence for a relative rise in crashes after 9pm on weekdays from 2002-2005. The upper bounds of our estimates rule out increases in all crashes larger than 1.0% and increases in fatal crashes larger than 1.3% - these upper bounds reject the increases implied by most existing studies. An analysis of regional trends in cell phone ownership and crashes, legislation banning driver cell phone use, and differences in urban and rural ownership confirm our basic result. We discuss possible explanations and present a behavioral model to reconcile this counterintuitive finding with existing research.

Nudges and Matrimonial Websites

2008-12-18T23:57:00.000-05:00

The Freakonomics blog has a great post on the behavioral economics behind minimum-payment requirements for credit cards. Citing some recent research by Neil Stewart, the post explains how providing a minimum threshold may induce people to actually make a smaller payment than they otherwise would have. This behavior comes about because of our susceptibility to anchoring: we tend to base our decisions on even arbitrary values we are given as starting points (see here for some examples).

This result is clearly of interest to behavioral economists: decades of research at the intersection of psychology and economics has led some observers to suggest that these tools be used in policy. That is, the irrational behavioral foibles of humans can be used to "nudge" them into making the right decisions (the term comes from a new book by Richard Thaler and Cass Sunstein).

Are there other avenues where nudges may be effective? And are there (other) examples where well-intentioned nudges may be counterproductive? A good illustration for both queries comes from Indian matrimonial websites. Like all social networking, a given user's experience on a martrimonial website depends on the activities of his or her peers. Inactive individuals do not contribute anything to the marketplace, while active ones generate all sorts of positive externalities. As such, it is in the best interest of the website company to get people active, either by introducing clarity to the user interface, making the website more fun, recruiting tons of singles, or by nudging existing users to make more contacts.

Regarding the latter, one particular website keeps track of whether a given user responds to an expression of interest from another user and the number of times that user accesses the website. Based on their activity patterns, slow or shy users are then sent an e-mail urging them to use the website by saying they are (1) missing out and (2) being rude to others by not responding. While perhaps not based in behavioral economics per se, the idea is to use some form of shame and opportunity cost argument to get people more involved.

But does this nudge work? I could easily see something like this being counterproductive. After all, nobody likes a nag, and I would bet there are plenty of people who would stop using the website just to avoid being made to feel guilty. Furthermore, messages (1) and (2) are conflicting: one is positive and the other negative. This might just confuse people.

I think this sort of thing is ripe for an experiment. However, this would require some alternate nudge option. Any ideas?

Yale and the Financial Crisis

2008-12-16T17:02:00.000-05:00

Check out the detailed consequences of Yale's 25% drop in the endowment value over the last six months or so here. The situation at other American universities also looks somewhat glum.

Be Careful With Natural Experiments

2008-12-16T15:45:00.000-05:00

Those of you who visit this space regularly know a thing or two about my obsession with causal effects. Answering many questions in health economics requires a strategy to understand the causal effect of one variable on another, and recovering such effects demands clever strategies or tools that go beyond simple multivariate models of some X on some Y. The cleanest way to get the causal effect of X on Y is to randomize X. This strategy has been used widely in laboratory and clinical medicine, and is now being exploited in a growing number of influential papers in economics and political science.

In many cases, however, it may not possible to randomize X or the question of interest involves some program or event that occurred in the past. In these situations, researchers looks for other sources of variation in X that are effectively random - the natural experiment. A good (and now famous) example from health economics involves the impact of early life events on health and socioeconomic position later in life. A great deal of early work in epidemiology found links between the disease environment faced by an individual at birth and this individuals health later in life. This link could be causal: fetal health influences organogenesis and development that goes on to influence adult health. At the same time, alternate explanations are possible: children born to poor parents become poor themselves, which affects their health. To complete the story, poor parents may tend to reside in poor, diseased areas.

To get around this issue, Douglas Almond, in an influential 2006 paper, utilized the influenza pandemic of 1918, which struck without warning, over a short period of time, and had large, notable effects. Being exposed to influenza in utero can be thought of as a random shock (a natural experiment), and Almond took advantage of this property to derive the causal effects of health in utero on outcomes later in life.

However, while the "influenza strategy" is as close to a slam dunk as you could possibly get in observational research, other things that may seem like natural experiments a priori may not be as definitively good. In fact, such variation may even lead researchers astray.

A new NBER working paper explores this issue in detail. Kasey Buckles and Daniel Hungerman consider the case of season of birth, which has been shown to be associated with a variety of health and socioeconomic outcomes later in life. These associations have been attributed to fetal exposure to different weather conditions or differential exposure to arbitrary age-cutoffs (in sports or in schooling). At first glance, season of birth appears to be a great source of exogenous variation for a slew of different causal questions: after all, individuals don't have any control over when they are born and it seems like something that would be left to chance. However, Buckles and Hungerman convincingly argue that this is not the case:

In this paper we consider a new explanation: that children born at different times in the year are conceived by women with different socioeconomic characteristics. We document large seasonal changes in the characteristics of women giving birth throughout the year in the United States. Children born in the winter are disproportionally born to women who are more likely to be teenagers and less likely to be married or have a high school degree. We show that controls for family background characteristics can explain up to half of the relationship between season of birth and adult outcomes. We then discuss the implications of this result for using season of birth as an instrumental variable; our findings suggest that, though popular, season-of-birth instruments may produce inconsistent estimates. Finally, we find that some of the seasonality in maternal characteristics is due to summer weather differentially affecting fertility patterns across socioeconomic groups.

This is a neat paper and serves as a good warning to those interested in finding natural variation to identify causal effects. Another excellent paper on the same subject, by Mark Rosenzweig and Ken Wolpin, goes through a variety of other potentially fallacious natural experiment examples and is a must read for anyone doing empirical work.

Bad News on the Other Side of the Birth Weight Distribution?

2008-12-11T23:19:00.000-05:00

Two recent articles explore the long-run effects of maternal weight gain and/or high weight at birth on long-run outcomes. Much of the health economics literature has focused on understanding returns to birth weight at the lower tail of the distribution, and several studies have found notable effects of birth weight on wages, schooling and cognition later in life. The downsides to high birth weight have been explored in the medical literature, which has typically focused on obesity and diabetes risk among children born to diabetic mothers (who birth larger than average - or macrosomic - infants).

A recent study in Obstetrics and Gynecology illustrates that increased gestational weight gain among mothers is associated with higher risk of obesity among their offspring. Unlike past studies, the study sample here is not limited to mothers with diabetes. While causality is difficult to establish here - mothers that gain weight during pregnancy may have similar preferences/constraints regarding food, which can be passed on to the next generation via other means besides biology - the results are interesting and deserve further research attention.

In a recent NBER working paper, Resul Cesar and Inas Rashad look at the association between birth weight and cognitive outcomes among a sample of children and teens and young adults followed in two different panel studies. The main result is that birth weight is associated with lower cognitive test scores at both the low and high part of the distribution: heavy infants suffer deficits, too.

I'm guessing this literature will likely explode in the next few years, especially with the ever growing obesity "epidemic" and its obvious consequences for maternal weight during pregnancy (see here for an earlier piece on this). Hopefully, this literature will address two major areas:

(1) Causal effects - Spatial variation in food prices, dynamics from recessions, the introduction of public programs and other shocks can be used to identify maternal weight gain during gestation and child birth weight. Utilizing this variation can help eliminate from the picture alternative interpretations of the association between maternal weight gain, child birth weight and later child outcomes.

(2) Mechanisms - Even if you can recover causal effects, what is the pathway? A link between high birth weight and lower cognition could be biological in nature or may operate through reduced and less effective investments in childhood and adolescents due to diminishing social returns to body weight: kids may learn less effectively if they are being made fun of at school for their appearance. These explanations have vastly different policy implications and should be teased apart.

Returns to Medical Care Among High Risk Infants

2008-12-09T10:43:00.000-05:00

A really interesting NBER paper this week looks at health returns to medical interventions among high-risk (here, low birth weight) newborns babies. The difficulty in assessing the casual effects of medical care in this population is that worse-off infants may get more of it because they require it. On the other hand, unhealthy babies may be more likely to come from poor families, who lack access to health care. Either process makes it difficult to recover causal effects.

Douglas Almond, Joseph Doyle, Amanda E. Kowalski and Heidi Williams adopt an interesting strategy to get around this issue. Essentially, they utilize existing birth weight thresholds (those below 1500 grams are classified very low birth weight) and provider obedience to these discontinuous (and perhaps arbitrary?) thresholds. By comparing those babies just below 1500 grams to those just above it, the authors contend that they get around the targetting of medical care to worse off babies - after all, the difference of a few grams around the cutoff is likely random and unrelated to innate biological hardiness. In a sense, the level of treatment given is essentially random for babies born around this narrow threshold. More on their methodology (which Almond and Doyle employ in another very interesting paper) and results:

We estimate marginal returns to medical care for at-risk newborns by comparing health outcomes and medical treatment provision on either side of common risk classifications, most notably the "very low birth weight" threshold at 1500 grams. First, using data on the census of US births in available years from 1983-2002, we find evidence that newborns with birth weights just below 1500 grams have lower one-year mortality rates than do newborns with birth weights just above this cutoff, even though mortality risk tends to decrease with birth weight. One-year mortality falls by approximately one percentage point as birth weight crosses 1500 grams from above, which is large relative to mean one-year mortality of 5.5% just above 1500 grams. Second, using hospital discharge records for births in five states in available years from 1991-2006, we find evidence that newborns with birth weights just below 1500 grams have discontinuously higher costs and frequencies of specific medical inputs. We estimate a $4,000 increase in hospital costs as birth weight approaches 1500 grams from above, relative to mean hospital costs of $40,000 just above 1500 grams. Taken together, these estimates suggest that the cost of saving a statistical life of a newborn with birth weight near 1500 grams is on the order of $550,000 in 2006 dollars.

Aside from the policy relevance of the results and the innovative research design used in the study, I find it really interesting that the provision of health care is so sensitive to seemingly arbitrary guidelines. Does anyone have a sense of where the 1500 and 2500 gram cutoffs came from, and whether they've outlived their clinical relevance?

Hiatus

2008-11-14T09:59:00.000-05:00

Hi everyone,

I will be taking a break from blogging for at least a month. I'm really grateful to those of you who visit this space regularly: I've learned a great deal from your comments.

I hope to resume blogging by the end of the year. If for some reason you miss my writing, you can check out my working academic papers here.

Thanks for reading, and see you soon.

Atheen

Random Tuesdays

2008-11-11T20:04:00.000-05:00

Some things of note:

1) Blogger and frequent commenter in this space James Hudspeth sent me this interesting article about how google searches can be used to track disease outbreaks, with information relays that are potentially faster than existing surveillance systems.

2) Elizabeth Pisani, author of The Wisdom of Whores (on my reading list for next month), has a fun and informative blog of the same name. Here is an interesting post from this blog looking at incentives and HIV/AIDS, with a special reference to disability grants in South Africa. Here is our paper on this subject.

3) Spotlight (with a thoughtful piece) on Obama.

4) People are addictive.

5) Be sure to check out the Yale University Insitute for Social and Policy Studies 40th Year Celebration and Conference. I think space is tight, but you can still get a sense of the bill through the papers and slides available via the link provided above. The conference focuses on using experiments to answer important questions in political science and economics, and the papers span a wide range of topics. All of them are super interesting.

Obama

2008-11-07T11:24:00.000-05:00

Addressing my graduating class, the Dean of the Duke University Chapel gave a stirring speech about how we needed to resist being labeled the 9/11 generation. Though the horrific terrorist attacks happened during our senior year, the Dean urged us to think beyond 9/11 and become the generation that made its mark by decisively and proactively moving society away from that event and towards a better future. Rather than becoming pessimistic and jaded about our world, he wanted us to use our energies, skills and talents to refocus the collective gaze of society on the good and the promising.

Nearly seven years later, I witnessed a slew of my friends taking up the Dean's challenge, inspired the first black man gaining a major party nomination for President, who embodied progress, optimism and youth, speaking of hope and change. Several friends participated directly in the Obama campaign, working long hours in battleground states, making calls and coordinating rallies. Others chose to engage in vociferous discussion with their families and friends about their beliefs and about what they felt was the most important decision our country has had to make in a long time. Still others spent election day calling complete strangers encouraging them to get out to vote. Tuesday night, and for the rest of the week thereafter, these friends and many others across the country walked around with gleaming smiles, radiating a sense of optimism that seems to be a perfectly natural extension of the events of the last few months, but also completely remarkable given the aftermath of 9/11 and the recent financial crisis. As one of my professors gushed on the day after the election: "It is now morning in America."

I think the implicit Reagan comparison is entirely appropriate. If Reagan was the transformational figure of our parents' generation, Obama is most definitely ours. Before Tuesday, though, my views on President-Elect Obama had been more muted. To me, "Hope" and "Change" were empty campaign promises that I'd heard before, made by another inspirational candidate who turned out to be an underwhelming President. If anything, I chose to vote for Obama mainly because I liked his technocratic and pragmatic outlook (and also because the erstwhile Maverick Senator McCain had become much less of one).

Tuesday taught me that these concepts are not, and had never been, just vague and hazy campaign rhetoric. Indeed, the tangible effects of being inspired by a man who has become both a symbol and a (potential) instrument for optimism and progress are substantive and significant and should not be underestimated: millions of people appear ready to make sacrifices and continue to work at a grassroots level for change. Some of the optimism appears a bit unhealthy - after all, Obama does not hold a magic wand - but I think much it can be harnessed and put to use in a way never before seen, certainly not in my lifetime.

Prior to Nov 4, 2008, 9/11 was indeed the defining historical moment of our generation. It clearly changed our views about the world and about our own country. Much of this decade has been colored by this event, from the tangible policies and actions we have taken as well as to our national mood more generally. We now have another defining moment for our generation: the election of Barack Obama to the Presidency, with all its optimism and its possibilities. Now let's put this all our good-will, excitement and sense of purpose to good use and get down in the trenches with our new President.

It's time to get to work.

Early Life and Obesity in Mexico: Talk Weds

2008-11-03T19:48:00.001-05:00

This Wednesday I'll be giving a talk on my research on the early life influences on obesity and hypertension among adults in Mexico. I will also speak on the links between early life conditions and health and cognitive development among adolescents in Mexico, again with a special emphasis on obesity. My presentation will follow a talk by my colleague Ulrike Muench, who will be presenting her very interesting research on gender gaps in wages paid to nurses (I believe male nurses get paid more) and the extent to which various theories may explain these differentials.

As of now, I think my talk will be pretty low-key. I plan on going through the basics of the biology linking birth and early childhood events to later health and discuss and then talk why this knowledge could be useful in enriching our understanding when and how economic factors (technological change leading to decreases in activity levels and food price declines leading to increases in income) work to lead to increases in body weight and any associated disorders. I will also present some preliminary econometric models attempting to (1) recover causal impacts of early life factors on these outcomes and (2) illustrate how the manner in which body weight (as well as blood pressure and glucose tolerance) respond to the aforementioned economic factors depends highly on environmental conditions faced at the beginning of life. Most importantly, I will unveil my research agenda for the next several months on these and related topics.

The seminar will be this Weds, Nov 5th from 1:30 - 3 PM in Rm 105 at 60 College Street (LEPH). Ulrike will open and I'll follow on as the second act. Feel free to join us if you are interested!