May 04, 2011

More good stuff from the World Bank's Development Impact blog: David McKenzie has a brilliant 'rant' on the external validity double standard, where people are more likely to fault randomized trials for illuminating only a particular context.

Is it really the case that external validity is so much more of a concern for experiments than for other micro-studies? Consider some of the most cited and well-known non-experimental empirical development research papers: Robert Townsend’s Econometrica paper on risk and insurance in India has over 1200 cites in Google Scholar, and is based on 120 households in 3 villages in rural India; Mark Rozenzweig and Oded Stark’s JPE paper on migration and marriage is based on the same Indian ICRISAT sample; Tim Conley and Chris Udry’s AER paper on technology adoption and pineapples is based on 180 households from 3 villages in southern Ghana; on a somewhat larger scale, Shankar Subramanian and Angus Deaton’s work on the demand for calories comes from 5630 households from one state in India in 1983.

The point is that we have learnt a lot from such studies.


Read the full post here.