Impact evaluation based on randomized controlled trials (RCTs) offers a powerful tool that has fundamentally reshaped development economics by offering novel solutions to long-standing problems of weak causal identification. Nonetheless, RCTs suffer important and underappreciated pitfalls, some...

This paper uses an unprecedentedly rich data set to estimate the cost of agricultural cargo preference (ACP) restrictions on United States food aid programs, and to document some of the programs' competitiveness and national security impacts. ACP cost U.S. taxpayers $140 million in 2006, 46%...