The Experimental Approach to Development Economics Abhijit V. Banerjee and Esther Duflo Department of Economics and Abdul Latif Jameel Poverty Action Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142; email:
[email protected],
[email protected] Annu. Rev. Econ. 2009. 1:151–78 Key Words First published online as a Review in Advance on randomized experiments, development economics, program April 21, 2009 evaluation The Annual Review of Economics is online at econ.annualreviews.org Abstract Annu. Rev. Econ. 2009.1:151-178. Downloaded from www.annualreviews.org This article’s doi: Randomized experiments have become a popular tool in develop- 10.1146/annurev.economics.050708.143235 ment economics research and have been the subject of a number of Copyright © 2009 by Annual Reviews. criticisms. This paper reviews the recent literature and discusses the Access provided by Massachusetts Institute of Technology (MIT) on 10/22/15. For personal use only. All rights reserved strengths and limitations of this approach in theory and in practice. 1941-1383/09/0904-0151$20.00 We argue that the main virtue of randomized experiments is that, owing to the close collaboration between researchers and implemen- ters, they allow the estimation of parameters that would not other- wise be possible to evaluate. We discuss the concerns that have been raised regarding experiments and generally conclude that, although real, they are often not specific to experiments. We conclude by dis- cussing the relationship between theory and experiments. 151 1. INTRODUCTION The past few years have seen a veritable explosion of randomized experiments in develop- ment economics. At the fall 2008 NEUDC conference, a large conference in development economics attended mainly by young researchers and PhD students, 24 papers reported on randomized field experiments, out of the 112 papers that used microeconomics data (laboratory experiments excluded).