An interesting, recently revised working paper by Duflo, Dupas and Kremer looks at the effects of providing school uniforms, teacher training on HIV education, and the two combined. This paper is useful in a number of dimensions – it gives us some sense of the longer term effects of these programs, the methodology is interesting (and informative), and finally, of course, the results are pretty intriguing and definitely food for thought.
Survey responses to questions on incomes (and other potentially sensitive topics) are likely to contain errors, which could go in either direction and be found at all levels of income. There is probably also non-random selection in terms of who agrees to be interviewed, implying that we get the weights wrong too (as used to "gross-up" the sample estimates to the population).
So I come back from vacation to find out that I was part of a randomized experiment in my absence. No, this had nothing to do with the wonders of airline travel in Europe (which don’t add that frisson of excitement through random cancellations like their American brethren), but rather two of our co-bloggers trying to figure out if the blog actually makes people recognize me and Jed more (here are links to parts
One of the interesting discussions I had this last week was with a World Bank consultant trying to think about how to evaluate the impact of large-scale infrastructure projects. Forming a counterfactual is very difficult in many of these cases, and so the question is what one could think of doing. Since I get asked similar types of questions reasonably regularly, I thought I’d share my thoughts on this issue, and see whether anyone has good examples to share.
- evaluation methods
The past couple of weeks have been unusually busy for August, but also fun. While Markus has been on vacation, Jed has produced a lot of interesting (and highly read) posts, and David and I ran a three-part series on the "Impact of Economics Blogs." The latter has been instructive. In particular, we realized -- mainly through feedback from readers -- that blogging about a paper in parts over time may be more effective in disseminating its messages and findings than the traditional one post/one link blog post.
The types of data available to development economists are proliferating – multi-topic household surveys are almost passé today but 25 years ago it was a rare privilege to be able to correlate economic measures of the household with other indicators such as health or community infrastructure. Not only are surveys more sophisticated, and arguably contain less error due to the use of field based computers, but the digital revolution has multiplied the types of data at our beck and call.
The latest issue of the Journal of Economic Perspectives (all content openly available online), has a symposium on the use of field experiments in economics. We’ve discussed or linked to posts on three of the four papers in previous blog posts: A paper on mechanism experiments by Ludwig, Kling and Mullainathan; a paper on the
- Research ethics