On the analogy between field experiments in economics and clinical trials in medicine

Abstract

Randomized experiments, as developed by Esther Duflo and Abhijit Banerjee at the Abdul Latif Jameel Poverty Action Lab (J-PAL), offer a novel, evidence-based approach to fighting poverty. This approach is original, in that it imports the methodology of clinical trials for application in development economics. This paper examines the analogy between J-PAL’s field experiments in development economics and randomized controlled trials (RCTs) in medicine. RCTs and randomized field experiments are commonly treated as identical, but such treatment neglects some of the major distinguishing features that make each experiment specifically apt for use in its respective field. The central claim of this paper is that the analogy between medicine and development economics is incomplete because the central dimensions of RCTs are not simply different but altogether lacking in J-PAL’s approach. This weakens both the political and the theoretical power of such experiments in development economics.