Thursday, February 26, 2009
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?
Friday, February 20, 2009
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.
Friday, February 13, 2009
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?
Thursday, February 12, 2009
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.
Monday, February 9, 2009
Chris Blattman with more about the film and Nathaniel's very interesting background (as well as video of the film's trailer).
Friday, February 6, 2009
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.
Thursday, February 5, 2009
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).
Monday, February 2, 2009
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.