The multi-faceted nature of Indian development brings with it many interesting puzzles. One such puzzle is the relationship between economic growth and caloric intake in India. While the Indian economy has grown leaps and bounds since the early 1980s, mean caloric consumption has not appeared to follow suit, even showing decreases across certain survey rounds. This is all a bit bizarre since, historically, for countries at India's level of development, caloric consumption has generally found to be increasing in GDP per capita. So what accounts for the contrarian trends in the Indian data?
Economists Angus Deaton and Jean Dreze suggest the following explanation in a recent working paper:
The reduction in calorie consumption cannot be attributed to declining real incomes, nor to any increase in the relative price of food. Our leading hypothesis, on which much work remains to be done, is that, as real incomes and wages have increased, leading to some nutritional improvement, there has been an offsetting reduction in calorie requirements due to declining levels of physical activity and possibly also to various improvements in the health environment. If correct, this analysis does not imply that Indians are currently adequately nourished; nothing could be further from the truth.
As I mentioned in earlier posts, countries in the developing world, including India, are experiencing increases in overweight, obesity and associated morbidities. If the Deaton-Dreze hypothesis is correct, researchers should be paying very careful attention to the impacts of technological change and preferences on energy expenditure and physical activity, among other things, in generating these rises in the prevalence of high body mass and adverse cardiovascular and metabolic profiles.
I will definitely say more about these issues in later posts, as I make progress on my own study on obesity in developing countries. Stay tuned.
Friday, May 23, 2008
Sunday, May 18, 2008
Great Article on Shen Tennis
Spring time in Upstate New York means high school tennis. My former team, the Shenendehowa Plainsmen, are once again in the running to win the Section II Class A title. I think we've won like 7 of these since I graduated in 1998, following a very long dry spell (which should tell you something about how much I contributed to our school's success!).
Anyway, today's Albany Times Union has a great article about Shen's starting third doubles player who, due to several congenital anomalies, plays and wins without most of his fingers, toes, and the ability to see out of his right eye. A really great story.
Also, the article quotes Gene Gould, Shen's longtime coach. It's great to see him still at the helm, coaching so many championship level teams.
Anyway, today's Albany Times Union has a great article about Shen's starting third doubles player who, due to several congenital anomalies, plays and wins without most of his fingers, toes, and the ability to see out of his right eye. A really great story.
Also, the article quotes Gene Gould, Shen's longtime coach. It's great to see him still at the helm, coaching so many championship level teams.
Monday, May 12, 2008
Hepatitis B and Pro-Male Sex Ratios Revisited
Many of you are probably aware of Emily Oster's controversial study on the potential (causal) effects of Hepatitis B on population gender ratios (see here for a non-technical summary). Oster's paper sparked a great debate as to whether the disease could truly explain a significant portion of the gender imbalance in many of the Asian countries, such as China, where the male/female ratios are remarkably large. Oster and Gang Chen recently revisited the Hepatitis B hypothesis as it applies to China. Their findings:
Earlier work (Oster, 2005) has argued, based on existing medical literature and analysis of cross country data and vaccination programs, that parents who are carriers of hepatitis B have a higher offspring sex ratio (more boys) than non-carrier parents. Further, since a number of Asian countries, China in particular, have high hepatitis B carrier rates, Oster (2005) suggested that hepatitis B could explain a large share - approximately 50% - of Asia's \missing women". Subsequent work has questioned this conclusion. Most notably, Lin and Luoh (2008) use data from a large cohort of births in Taiwan and find only a very tiny effect of maternal hepatitis carrier status on offspring sex ratio. Although this work is quite conclusive for the case of mothers, it leaves open the possibility that paternal carrier status is driving higher sex offspring sex ratios. To test this, we collected data on the offspring gender for a cohort of 67,000 people in China who are being observed in a prospective cohort study of liver cancer; approximately 15% of these individuals are hepatitis B carriers. In this sample, we find no effect of either maternal or paternal hepatitis B carrier status on offspring sex. Carrier parents are no more likely to have male children than non-carrier parents. This finding leads us to conclude that hepatitis B cannot explain skewed sex ratios in China.
For what it's worth, I applaud Oster, who is clearly a top-flight researcher doing interesting work, for her academic courage and honesty. It's just great to see an example where one's ego does not interfere with his/her quest to learn the Truth. Good lesson for graduate students such as myself.
Furthermore, despite this retraction (at least with respect to China), Oster is not leaving the topic behind. Indeed, the fact that Hepatitis B explains a good deal of the gender imbalance in some countries but not others is intriguing and worthy of further exploration. This is exactly what she is doing this new working paper, which attempts to reconcile the scientific and population evidence on Hep B and sex ratios.
Excellent research on an interesting line of work. I'd be curious to see how this plays out in the future.
[Ed - 5/13/08 - I was recently informed that the Marginal Revolution blog put up a very similar post yesterday on this topic. Just for the record, I wrote this post as soon as I saw Oster's NBER working paper, and prior to me finding out what other blogs had to say. Also, just as an FYI, you might want to check out the comments under said MR post. The discussion there is pretty interesting.]
Earlier work (Oster, 2005) has argued, based on existing medical literature and analysis of cross country data and vaccination programs, that parents who are carriers of hepatitis B have a higher offspring sex ratio (more boys) than non-carrier parents. Further, since a number of Asian countries, China in particular, have high hepatitis B carrier rates, Oster (2005) suggested that hepatitis B could explain a large share - approximately 50% - of Asia's \missing women". Subsequent work has questioned this conclusion. Most notably, Lin and Luoh (2008) use data from a large cohort of births in Taiwan and find only a very tiny effect of maternal hepatitis carrier status on offspring sex ratio. Although this work is quite conclusive for the case of mothers, it leaves open the possibility that paternal carrier status is driving higher sex offspring sex ratios. To test this, we collected data on the offspring gender for a cohort of 67,000 people in China who are being observed in a prospective cohort study of liver cancer; approximately 15% of these individuals are hepatitis B carriers. In this sample, we find no effect of either maternal or paternal hepatitis B carrier status on offspring sex. Carrier parents are no more likely to have male children than non-carrier parents. This finding leads us to conclude that hepatitis B cannot explain skewed sex ratios in China.
For what it's worth, I applaud Oster, who is clearly a top-flight researcher doing interesting work, for her academic courage and honesty. It's just great to see an example where one's ego does not interfere with his/her quest to learn the Truth. Good lesson for graduate students such as myself.
Furthermore, despite this retraction (at least with respect to China), Oster is not leaving the topic behind. Indeed, the fact that Hepatitis B explains a good deal of the gender imbalance in some countries but not others is intriguing and worthy of further exploration. This is exactly what she is doing this new working paper, which attempts to reconcile the scientific and population evidence on Hep B and sex ratios.
Excellent research on an interesting line of work. I'd be curious to see how this plays out in the future.
[Ed - 5/13/08 - I was recently informed that the Marginal Revolution blog put up a very similar post yesterday on this topic. Just for the record, I wrote this post as soon as I saw Oster's NBER working paper, and prior to me finding out what other blogs had to say. Also, just as an FYI, you might want to check out the comments under said MR post. The discussion there is pretty interesting.]
Sunday, May 11, 2008
Bad Timing
My doorbell rang last Friday around 9 PM. I happened to be home and, figuring it was my roommate or some other tenant having forgotten their key to get inside, I decided to head downstairs and answer.
To my surprise, I was greeted by two well-dressed white males in their 20s, one of whom as carrying a clip-board. They explained that they were representing a state-wide environmental lobby and went on to talk about a bill they were trying to get passed and how they needed my $15 dollars to do it.
I normally don't provide money to solicitors who accost me in person or over the phone, so the chances that these two would ever get anything from me was pretty low to begin with. However, in this instance, the probability that I would part with my money was pretty much zero given the bizarre timing of their request.
Who comes to your door on Friday night to collect money for the environment? Hardly anyone, I would think. First off, most people are either not around on Friday or want to enjoy the start of their weekends by winding down with family, friends or with a good movie or book. So to have someone at your door at that time is a bit unexpected and, as such, a little scary. Indeed, at one point I thought these guys were going to overpower me and then clean out my apartment.
Not only that, I wasn't sure how this strategy was a good idea from their standpoint, either. For a solicitor, I'd bet the returns to going around on a Friday night are quite low since people will either not be around or too shocked/annoyed to want to listen to any kind of pitch.
So I asked the two solicitors: "This is a bit strange. Why are you guys doing this on Friday night?"
Their answer: "The environment never rests."
They still didn't get any money from me.
To my surprise, I was greeted by two well-dressed white males in their 20s, one of whom as carrying a clip-board. They explained that they were representing a state-wide environmental lobby and went on to talk about a bill they were trying to get passed and how they needed my $15 dollars to do it.
I normally don't provide money to solicitors who accost me in person or over the phone, so the chances that these two would ever get anything from me was pretty low to begin with. However, in this instance, the probability that I would part with my money was pretty much zero given the bizarre timing of their request.
Who comes to your door on Friday night to collect money for the environment? Hardly anyone, I would think. First off, most people are either not around on Friday or want to enjoy the start of their weekends by winding down with family, friends or with a good movie or book. So to have someone at your door at that time is a bit unexpected and, as such, a little scary. Indeed, at one point I thought these guys were going to overpower me and then clean out my apartment.
Not only that, I wasn't sure how this strategy was a good idea from their standpoint, either. For a solicitor, I'd bet the returns to going around on a Friday night are quite low since people will either not be around or too shocked/annoyed to want to listen to any kind of pitch.
So I asked the two solicitors: "This is a bit strange. Why are you guys doing this on Friday night?"
Their answer: "The environment never rests."
They still didn't get any money from me.
Tuesday, May 6, 2008
Fetal Origins Plus
I've spent some time on this blog talking about the influence of fetal and early childhood events on later health and economic outcomes (see, for example, here). Recently, I was scouring the web for some of the medical literature on this subject, and came across this great website. The site summarizes the seminal body of work conducted by David Barker and colleagues on the fetal origins hypothesis, providing non-technical summaries of a variety of research strands and key citations to the most important papers written on the subject. Definitely check it out.
As I mentioned in the linked post above, the fetal programming literature has gained great currency among economists. However, little work has been done on fetal origins in the context of other investments and events and individual receives or faces in the course of his or her life cycle. James Heckman's recent paper in the Proceedings of the National Academy of Sciences synthesizes these literatures, linking health, cognition and other skills in the process (you can find a more general statement of Heckman's research agenda here). It's a great read that highlights the fact that there is a great deal of research required to fully understand and characterize many aspects of human capital accumulation. (Self-promotion: this is good news for me, as much of my dissertation deals with these topics.)
As I mentioned in the linked post above, the fetal programming literature has gained great currency among economists. However, little work has been done on fetal origins in the context of other investments and events and individual receives or faces in the course of his or her life cycle. James Heckman's recent paper in the Proceedings of the National Academy of Sciences synthesizes these literatures, linking health, cognition and other skills in the process (you can find a more general statement of Heckman's research agenda here). It's a great read that highlights the fact that there is a great deal of research required to fully understand and characterize many aspects of human capital accumulation. (Self-promotion: this is good news for me, as much of my dissertation deals with these topics.)
Saturday, May 3, 2008
A Prospectus for the Rest of Us!
In a few weeks, I will have officially completed my third year as a PhD student (or my fifth year of my MD/PhD quest, which sounds a lot sadder). Part and parcel with this achievement comes a fairly major institutional requirement: I have to submit my 20 page research prospectus by mid June. Completion of the prospectus promotes me to "candidacy." (I only recently realized the significance of this term. My e-mail footer for the last three years had ended with "PhD Candidate." Apparently, by doing so, I've "lied to thousands of people" since coming to Yale).
Like most things I do, I've approached the whole prospectus writing process in a seriously manic, yet somehow careless, fashion. The way this is supposed to work is that you first come up with a question, then talk to your committee (or those who you intend to con into being on your committee), then write the prospectus based on those ideas, and then carry out the research. My process has been almost opposite: do the research, form the committee, get confused between several ideas, talk to the committee, toss around two more large ideas, and, ultimately, set off on writing the prospectus. In some sense, I've treated the prospectus as something that comes into place once I've generated enough data. The problem with doing this is that your ideas might be so disparate that they do not naturally fit together into a thematic dissertation (though you can make the theme as vague as you want, perhaps, to get around this) or you explore so many things that you are confused between different directions you could pursue. This is my problem now. I am fairly confident about two of my papers, but the lead paper - well, that remains something to be decided!
That being said, for the purposes of the prospectus, none of this actually matters! The point is to have something coherent down that the graduate committee thinks is interesting, doable and illustrative of your knowledge of the field. Not everything you write in the prospectus has to work out. Given this, perhaps the best thing to do is to find something you are broadly interested in, figure out some specific questions and data sources you could use, get the prospectus done early and then go to town. This is what I would advocate to other grad students in the pipeline and I am certainly in position to do this right now.
But, for whatever reason, I don't want to submit my prospectus until I am confident that all three papers I propose will materialize in the final dissertation. Given what I just said, this is irrational: I think this is a pretty good example of cognitive dissonance or, more precisely, some kind of pre-emptive action to avoid cognitive dissonance. I don't want to hand in something other than what I said I would hand in - I don't want to appear inconsistent over time.
Well, it's time to bite the bullet. I am currently working on finishing up this prospectus. I plan on studying the astonishingly quick transition of low and middle income countries from malnutrition to obesity, particularly focusing on the intersection between biology and economic factors that may drive such changes (paper 1), as well as intergenerational transfers of health status. (papers 2 and 3).
Hopefully, whatever I produce and hand in will follow this script. And if it doesn't...well, I guess thats OK, too.
Like most things I do, I've approached the whole prospectus writing process in a seriously manic, yet somehow careless, fashion. The way this is supposed to work is that you first come up with a question, then talk to your committee (or those who you intend to con into being on your committee), then write the prospectus based on those ideas, and then carry out the research. My process has been almost opposite: do the research, form the committee, get confused between several ideas, talk to the committee, toss around two more large ideas, and, ultimately, set off on writing the prospectus. In some sense, I've treated the prospectus as something that comes into place once I've generated enough data. The problem with doing this is that your ideas might be so disparate that they do not naturally fit together into a thematic dissertation (though you can make the theme as vague as you want, perhaps, to get around this) or you explore so many things that you are confused between different directions you could pursue. This is my problem now. I am fairly confident about two of my papers, but the lead paper - well, that remains something to be decided!
That being said, for the purposes of the prospectus, none of this actually matters! The point is to have something coherent down that the graduate committee thinks is interesting, doable and illustrative of your knowledge of the field. Not everything you write in the prospectus has to work out. Given this, perhaps the best thing to do is to find something you are broadly interested in, figure out some specific questions and data sources you could use, get the prospectus done early and then go to town. This is what I would advocate to other grad students in the pipeline and I am certainly in position to do this right now.
But, for whatever reason, I don't want to submit my prospectus until I am confident that all three papers I propose will materialize in the final dissertation. Given what I just said, this is irrational: I think this is a pretty good example of cognitive dissonance or, more precisely, some kind of pre-emptive action to avoid cognitive dissonance. I don't want to hand in something other than what I said I would hand in - I don't want to appear inconsistent over time.
Well, it's time to bite the bullet. I am currently working on finishing up this prospectus. I plan on studying the astonishingly quick transition of low and middle income countries from malnutrition to obesity, particularly focusing on the intersection between biology and economic factors that may drive such changes (paper 1), as well as intergenerational transfers of health status. (papers 2 and 3).
Hopefully, whatever I produce and hand in will follow this script. And if it doesn't...well, I guess thats OK, too.
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