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.
Friday, September 25, 2009
Monday, September 21, 2009
Psychiatric Pharmacotherapy and Crime
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.
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.
Saturday, September 19, 2009
Variance in Physician Behaviors
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?
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?
Wednesday, September 16, 2009
How the Steelers Can Win An Additional Game this Season
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.
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.
Saturday, August 8, 2009
Life Expectancy, US Health Care and Other Interesting Links
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.
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.
Monday, July 27, 2009
World Oil Prices and Child Health
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.
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.
Friday, July 24, 2009
Worthy Links on Health Care Reform
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.
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.
Sunday, July 19, 2009
Economic Shocks, Risky Sexual Behavior and the HIV/AIDS Epidemic
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.
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.
Tuesday, July 14, 2009
"Sin Taxes," Public Health, and Targeting
"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.
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.
Sunday, July 12, 2009
Two Year Anniversary
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.
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.
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