Randomization and Social Policy Evaluation Revisited

This paper considers the evidence on the effectiveness and limitations of randomized controlled trials in economics. I revisit my previous paper quot;Randomization and Social Policy Evaluationquot; and update its message. I present a brief history of randomization in economics and identify two waves of enthusiasm for the method as quot;Two Awakeningsquot; because of the near-religious zeal associated with both waves. I briefly summarize the lessons of the first wave and forecast the same lessons will be learned in the second wave