Self-Selection in School Choice

Abstract

We study self-selection in centralized school choice, a strategy that takes place when students submit preferences before knowing their priorities at schools. A student self-selects if she decides not to apply to some schools despite being desirable. We give a theoretical explanation for this behavior: if a student believes her chances of being assigned to some schools are zero, she may not rank them even when the mechanism is strategyproof. Using data from the Mexico City high school match, we find evidence that self-selection exists, and has redistributive consequences. First, given the same past grade, students from low socioeconomic backgrounds are more likely to self-select. Second, some students self-select by mistake, and obtain a high priority once the uncertainty is resolved, but nonetheless are not assigned to their most preferred choice exactly because of self-selection. Students from low socioeconomic backgrounds are particularly vulnerable to this type of mistake. These findings question the effectiveness of equal access provided by school choice, and we argue it can be improved by changing the timing of submission.