We use the exchange between Kearney/Levine and Jaeger/Joyce/Kaestner on “16 and Pregnant” to reexamine the use of DiD as a response to the failure of nature to properly design an experiment for us. We argue that 1) any DiD paper should address why the original levels of the experimental and...

Randomized controlled trials are increasingly used to evaluate policies. How can we make these experiments as useful as possible for policy purposes? We argue greater use should be made of experiments that identify behavioral mechanisms that are central to clearly specified policy questions,...

We propose a new classification of experiments that captures the extent to which the experimental design and analysis are linked to economic theory. We then use this system to classify all published field experiments in the five top economics journals from 1975 to 2010. We find that the vast...

Empiricism in the sciences allows us to test theories, formulate optimal policies, and learn how the world works. In this manner, it is critical that our empirical work provides accurate conclusions about underlying data patterns. False positives represent an especially important problem, as...

Markets sometimes unravel, with offers becoming inefficiently early. Often this is attributed to competition arising from an imbalance of demand and supply, typically excess demand for workers. However this presents a puzzle, since unraveling can only occur when firms are willing to make early...

This paper examines potential tradeoffs between research methods in answering important questions versus providing more cleanly identified estimates on problems that are potentially of lesser interest. The strengths and limitations of experimental and quasi-experimental methods are discussed and...

This paper makes the case for greater use of randomized experiments “at scale.” We review various critiques of experimental program evaluation in developing countries, and discuss how experimenting at scale along three specific dimensions – the size of the sampling frame, the number of...

This paper describes results of a pair of incentivized experiments on biases in judgments about random samples. Consistent with the Law of Small Numbers (LSN), participants exaggerated the likelihood that short sequences and random subsets of coin flips would be balanced between heads and tails....

Randomized experiments have become a popular tool in development economics research, and have been the subject of a number of criticisms. This paper reviews the recent literature, and discusses the strengths and limitations of this approach in theory and in practice. We argue that the main...