A guide to megastudies.

How can behavioral insights best be leveraged to solve pressing policy challenges? Because research studies are typically designed to test the validity of a particular idea, surprisingly little is known about the relative efficacy of different approaches to changing behavior in any given policy context. We discuss megastudies as a research approach that can surmount this and other obstacles to developing optimal behaviorally informed policy interventions. We define a megastudy as "a massive field experiment in which many different treatments are tested synchronously in one large sample using a common, objectively measured outcome." We summarize this apples-to-apples approach to research and lay out recommendations, limitations, and promising future directions for scholars who might want to conduct or evaluate megastudies.