Better LATE Than Nothing: Some Comments on Deaton (2009) and Heckman and Urzua (2009)
Two recent papers, Deaton (2009), and Heckman and Urzua (2009), argue against what they see as an excessive and inappropriate use of experimental and quasi-experimental methods in empirical work in economics in the last decade. They specifically question the increased use of instrumental variables and natural experiments in labor economics, and of randomized experiments in development economics. In these comments I will make the case that this move towards shoring up the internal validity of estimates, and towards clarifying the description of the population these estimates are relevant for, has been important and beneficial in increasing the credibility of empirical work in economics. I also address some other concerns raised by the Deaton and Heckman-Urzua papers.
I have benefitted from discussions with Joshua Angrist, Susan Athey, Abhijit Banerjee, David Card, Gary Chamberlain, Esther Duflo, Kei Hirano, Geert Ridder, Chuck Manski, Sendhil Mullainathan, and Jeffrey Wooldridge, although they bear no responsibility for any of the views expressed here. Financial support for this research was generously provided through NSF grant 0820361. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.
Guido W. Imbens, 2010. "Better LATE Than Nothing: Some Comments on Deaton (2009) and Heckman and Urzua (2009)," Journal of Economic Literature, American Economic Association, vol. 48(2), pages 399-423, June. citation courtesy of