I presented my paper, The Determinants of Sex Selective Abortions, at the Pacific Development Conference. This year PacDev was held at University of Southern California and John Strauss and Jeff Nugent did an excellent job in organising. More information on the paper is on the post below.
I presented my paper "The Determinants of Sex Selective Abortions" at the NEUDC conference at Tufts University in Boston 7 November and at University of Copenhagen and University of Aarhus in Denmark in the beginning of December. The paper is still work in progress but a working paper version should be available soon. Until then the presentation is here and the abstract below.
Over the last decades many countries have seen a significant shift in the sex ratio at birth as techniques for pre-natal sex determination have become more widely available. Despite this there has been relatively little research on what determines the use of sex selective abortions at the individual level. A major impediment to analysing determinants of sex selective abortions is the absence of reliable direct information on individuals' use of pre-natal sex determination and abortions, which means that information have to be inferred from other observed outcomes. Previous studies have used the sex of children born and estimated which factors affect the likelihood of having a boy at a given parity. I argue that this method fails to address the close relationship between fertility, birth spacing and the use of sex selective abortions, and leads to biased estimates and low power in the estimations. To examine the determinants of the use of sex selective abortions I therefore estimate a competing risk hazard model, which directly incorporates both fertility and abortion decisions and the potential censoring of birth spacing. This is done using data from the three rounds of the Indian National Family and Health Survey. The results show that women who are likely to want fewer children are significantly more likely to be using sex selective abortions and that these numbers are substantially larger than previously found. Furthermore, contrary to resent research this paper finds no evidence of declining use of sex selective abortions; in fact, sex selective abortions appear to have increased for parity two, once one controls for censoring.
I gave a presentation in our weekly labour/development brown bag series on a NSF grant that I am co-PI on. This is very different from most of the other things I work on, but I think it has great potential. You can find the presentation here.
This project merges the fields of Economics and Human-Computer Interaction (HCI) into a new field of Interaction Economics. This field studies the costs and benefits of computer systems that define how people decide to use them. This project makes three contributions that form the basis of Interaction Economics. First, we will scientifically measure the objective, quantitative amount that a user interface motivates or demotivates a user to accomplish a task with it. This capability has broad implications, and our method is faster and cheaper than traditional user studies. Second, we will create economic models of these motivations, predicting how systems of interfaces differentially affect production. Third, we will repeatably experiment with social systems by creating multiple copies of them with controlled and manipulated variables, and running the systems to observe the effects of our changes. These three contributions will let us experimentally optimize current systems, and design new systems, of greater complexity and novelty, with greater certainty of success. Our methodology relies on a novel use of Internet labor markets, specifically Amazon‘s Mechanical Turk, a place where interactive tasks (HCI) meet incentives and markets (Economics). With controlled payments to real people we can simulate and study a wide range of social-computational phenomena that was not possible before.
The Atlantic has a very nice article summarising the discussion of whether the flu vaccine prevents death among older people. The basic problem in evaluating interventions like these is self-selection, which can make "cohort studies" unreliable. Not really news to most economists, but it seemed to have created quite a fire storm among public health and MD researchers. A very worthwhile read.
Whether this season’s swine flu turns out to be deadly or mild, most experts agree that it’s only a matter of time before we’re hit by a truly devastating flu pandemic—one that might kill more people worldwide than have died of the plague and aids combined. In the U.S., the main lines of defense are pharmaceutical—vaccines and antiviral drugs to limit the spread of flu and prevent people from dying from it. Yet now some flu experts are challenging the medical orthodoxy and arguing that for those most in need of protection, flu shots and antiviral drugs may provide little to none. So where does that leave us if a bad pandemic strikes?
A substantially revised version of "Literacy, Skills and Welfare: Effects of Participation in Adult Literacy Programs" is available. It is joint work with Niels-Hugo Blunch. The abstract is here:
This paper examines the effect of adult literacy program participation on household consumption in Ghana. The adult literacy programs in Ghana are of special interest since they are more comprehensive than standard literacy programs and incorporate many additional topics. We use community fixed effects combined with instrumental variables to account for possible endogenous program placement and self-selection into program participation. For households where none of the adults have completed any formal education we find a substantial, positive and statistically significant effect on household consumption. Our preferred estimate of the effect of participation for households without education is equivalent to a ten percent increase in consumption per adult equivalent. The effects of participation on welfare for other households are smaller and not statistically significant, and become smaller the more educated the household is. We find positive and statistically significant effects of participation on literacy and numeracy rates, although the increases are too small to be the only explanation for the welfare effects. There is also evidence that participants are more likely to engage in market activities and to sell a variety of agricultural goods. Taking account of both direct cost and opportunity cost we argue that the social returns to adult literacy programs are substantial.
Apparently the relationship between price and demand seems to be a slippery concept. Elizabeth Kolbert (in an otherwise interesting piece) on obesity in the New Yorker has this to say about the argument that part of the reason for the increase in obesity is that the cost per calorie has gone down:
The correlation between cost and consumption is pretty compelling; as Finkelstein notes, there’s no more basic tenet of economics than that price matters. But, like evolution, economics alone doesn’t seem adequate to the obesity problem. If it’s cheap to consume too many calories’ worth of ice cream or Coca-Cola, it’s even cheaper to consume fewer. [my emphasis]
Oh well!
Well, I know much of the attention these days are to the economy, but this crash hit a little closer to home. I was stopped on the highway because of traffic when I got rear-ended. I got transported to the ER with a c-collar and on a backboard, but luckily there were no broken bones involved. [gallery]
If nothing else it also shows why people should pay attention and not tailgate, especially on a highway!
My paper on children's time use is now available on-line. The abstract for the paper is:
This paper uses a longitudinal survey from the Philippines with detailed information on family time use to analyse the effects of economic factors on children's time allocation. This is done while taking account of censoring, unobservable family heterogeneity and simultaneous decisions with respect to time spent in different activities. It is shown that there is a statistically significant correlation between unobservable individual and household characteristics when it comes to hours spent working and in school, but that this correlation is substantially smaller than one. Including household heterogeneity leads to substantial changes in the estimated effects of many of the important explanatory variables.
I presented my paper "Natural Hazards and Child Health" and a poster on my paper "The Demand for Sex Selective Abortions" at the Population Association of America's annual meeting (held in Detroit). It was a great conference in a horrible hotel.
Last week's Science section of the New York Times had an article about variations in sex ratios by latitude, based on an article in Biological Letters. Essentially, the upshot is that people in Africa are less likely than people in Europe and Asia to have a boy (even after excluding data that might be affected by sex selective abortions). Garenne wrote about sex ratios in Africa in Human Biology in 2002 and found broadly similar results. You can read the NYT article here.
I gave a seminar at UBC 17 March on my paper "Gone with the Wind? Hurricane Risk, Fertility and Education". I am in the process of revising the paper based on comments from seminar participants and referee reports I have gotten. An revised version should be ready in the not too distant future.
I presented my paper on "Natural Hazards and Child Health" at the Pacific Development Conference at SFSU in San Francisco this last Saturday. Anoshua Chaudhuri did a great job at arranging the conference (Anoshua is a graduate from the UW graduate programme and is an assistant professor at SFSU). The only "problem" with the conference is that it is almost too short; only one day which does not allow a lot of time to chat with people.
I gave a seminar at the Population Studies Center at University of Michigan Monday 9 March 2009. The paper, "The Demand for Sex Selective Abortions," is still work in progress, but the presentation is here. Note that since this is work in progress methods and results might/will change, especially in light of the very useful comments I got during my visit. The abstract is:
One of the major changes that have taken place in India over the last two decades is a significant shift in the sex ratio at birth, as techniques for prenatal sex determination have become more widely available. There has, however, been little analysis of which factors influence the decision to abort female fetuses at the individual level. Furthermore, the sparse literature does not address the relationship between fertility, spacing and the demand for sex selective abortions, which may lead to biased estimates of the determinants of sex selective abortions. Using data from the three rounds of the National Family and Health Survey this paper relies on the observed spacing between births to examine the determinants of the demand for sex selective abortions. By employing a discrete hazard model it is possible to simultaneously control for the fertility and abortion decisions, while taking account of censoring and unobservable characteristics that might affect either.
David Lam (University of Michigan) will be giving a seminar Friday 20 February at 2.00 PM in Condon 309. The title of his talk is "Schooling as a Lottery: Racial Differences in School Advancement in Urban South Africa". The abstract is below:
This paper develops a stochastic model of grade repetition to analyze the large racial differences in progress through secondary school in South Africa. The model predicts that a larger stochastic component in the link between learning and measured performance will generate higher enrollment, higher failure rates, and a weaker link between ability and grade progression.Using recently collected longitudinal data we find that progress through secondary school is strongly associated with scores on a baseline literacy and numeracy test. In grades 8-11 the effect of these scores on grade progression is much stronger for white and coloured students than for African students, while there is no racial difference in the impact of the scores on passing the nationally standardized grade 12 matriculation exam. The results provide strong support for our model, suggesting that grade progression in African schools is poorly linked to actual ability and learning. The results point to the importance of considering the stochastic component of grade repetition in analyzing school systems with high failure rates.