A DISTRIBUTIONAL ANALYSIS OF TREATMENT EFFECTS IN RANDOMIZED EXPERIMENTS

This paper considers statistical tests that can be used to identify if a treatment is effective for a specific outcome variable over the entire distribution of a treated group when it is compared with a control group's distribution. Using only the average treatment effect to evaluate specific treatment programs ignores what happens in different regions of the distribution of interest. To address this problem, tests of equality of distributions, first and second order stochastic dominance are employed. To show how to implement the tests easily, an outline on how to estimate critical values using bootstrap method is presented. The tests are then applied to analyze the effectiveness of a treatment in a randomized experiment.