This paper provides rigorous evidence (for 12,130 participants in a series of naturally occurring randomized lotteries) that a large‐scale high school reform initiative (New York City's creation of 100+ small high schools of choice between 2002 and 2008) can markedly and consistently increase...

Evaluations of public programs in many fields reveal that different types of programs—or different versions of the same program—vary in their effectiveness. Moreover, a program that is effective for one group of people might not be effective for other groups, and a program that is effective...

This paper is an examination of how autoregressive earnings models commonly used to evaluate job-training programs can produce badly biased estimates of both the magnitude and the temporal pattern of program impacts. Ashenfelter's results are used to illustrate this point, and a new, more...