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.