Selective Trials: A Principal-Agent Approach to Randomized Controlled Experiments
Abstract
We study the design of randomized controlled experiments when outcomes are significantly affected by experimental subjects' unobserved effort expenditure. While standard randomized controlled trials (RCTs) are internally consistent, the unobservability of effort compromises external validity. We approach trial design as a principal-agent problem and show that natural extensions of RCTs—which we call selective trials—can help improve external validity. In particular, selective trials can disentangle the effects of treatment, effort, and the interaction of treatment and effort. Moreover, they can help identify when treatment effects are affected by erroneous beliefs and inappropriate effort expenditure.
Additional Information
© 2012 American Economic Association. We are particularly indebted to Abhijit Banerjee, Roland Benabou, and Jeff Ely for advice and encouragement. The paper benefited greatly from conversations with Attila Ambrus, Nava Ashraf, Oriana Bandiera, Angus Deaton, Esther Duflo, Pascaline Dupas, Greg Fischer, Kripa Freitas, Drew Fudenberg, Paul Gertler, Justin Grimmer, Rema Hanna, Jim Heckman, Johannes Hörner, Dean Karlan, Michael Kremer, Guido Imbens, John Ledyard, Maggie McConnell, Stephen Morris, Muriel Niederle, Marcin Peski, Nancy Qian, Antonio Rangel, Imran Rasul, Dan Scharfstein, Sam Schulhofer-Wohl, Jesse Shapiro, Monica Singhal, Andy Skrzypacz, Francesco Sobbrio, Lars Stole, Steven Tadelis, Chris Woodruff and Eric Zitzewitz, as well as seminar participants at Berkeley Haas, Boston University, Brown, Caltech, Chicago Booth, Cornell, Harvard/MIT, HEC Lausanne, Johns Hopkins, LSE, MPSA, NYU Stern, Princeton, The Radcliffe Institute, Stanford, Stockholm School of Economics, SWET, UT Austin, Washington University in St. Louis, the World Bank and Yale. Part of this work was done while Chassang visited the Department of Economics at Harvard, and he gratefully acknowledges their hospitality. Paul Scott provided excellent research assistance.Attached Files
Published - Selective_Trials_Chassang_Padro_Snowberg-NBER.pdf
Published - aer.102.4.1279.pdf
Submitted - Selective_Trials3_Chassang_Padro_Snowberg.pdf
Supplemental Material - Selective_Trials_Online_Appendix.pdf
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- CaltechAUTHORS:20120530-092040716
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2012-12-06Created from EPrint's datestamp field
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2021-11-09Created from EPrint's last_modified field