Testing for sample selection in the Milwaukee school choice experiment

We examine data collected from the Milwaukee Parental Choice Program to determine whether students with unobserved characteristics correlated with achievement are more likely to apply to the voucher program. We first estimate probit models for application to the choice program, and then math and reading achievement models. By comparing students randomly rejected from the program with students who did not apply, we can test whether applicants and non-applicants have unobservable characteristics that are correlated both with the choice of school sector and with the included explanatory variables. We do not find strong evidence that students who apply to participate in the Milwaukee choice program have unmeasured characteristics, such as motivation, which systematically differ from non-applicants [JEL C12, I21].