The promise of randomized controlled trials is that evidence gathered through the evaluation of a specific program helps us—possibly after several rounds of fine-tuning and multiple replications in different contexts—to inform policy. However, critics have pointed out that a potential...

Causal estimates of the benefits of increased schooling using U.S. state schooling laws as instruments typically rely on specifications which assume common trends across states in the factors affecting different birth cohorts. Differential changes across states during this period, such as...

Many papers use fixed effects (FE) to identify causal impacts of an intervention. In this paper we show that when the treatment status only varies within some groups, this design can induce non-random selection of groups into the identifying sample, which we term selection into identification...

Estimating the returns to education remains an active area of research amongst applied economists. Most studies that estimate the causal return to education exploit changes in schooling and/or labor laws to generate exogenous differences in education. An implicit assumption is that more time in...