The randomized controlled trial (RCT) has been a heavily utilized research tool in medicine for over 60 years. Since the early 2000's, large-scale RCTs have been used in increasingly large numbers in the social sciences to evaluate questions of both policy and theory. The early economics...

Estimation of empirical relationships is prone to bias. Economists have carefully studied sources of bias in structural and quasi-experimental approaches, but the randomized control trial (RCT) has only begun to receive such scrutiny. In this paper, we argue that several lessons from medicine,...