Evaluating Econometric Evaluations of Post-Secondary Aid
通过随机实验评估大型私人助学金的影响，并将结果与基于可观测变量选择和断点回归的非实验估计进行比较，发现断点回归在阈值附近与实验一致但受变量粗糙度影响。
In an ongoing evaluation of post-secondary financial aid, we use random assignment to assess the causal effects of large privately-funded aid awards. Here, we compare the unbiased causal effect estimates from our RCT with two types of non-experimental econometric estimates. The first applies a selection-on-observables assumption in data from an earlier, nonrandomized cohort; the second uses a regression discontinuity design. Selection-on-observables methods generate estimates well below the experimental benchmark. Regression discontinuity estimates are similar to experimental estimates for students near the cutoff, but sensitive to controlling for the running variable, which is unusually coarse.