The Performance of School Assignment Mechanisms in Practice

Abstract

Theory points to a potential trade-off between two main school assignment mechanisms; Boston and Deferred Acceptance (DA). While DA is strategy-proof and gives a stable matching, Boston might outperform DA in terms of ex-ante efficiency. We quantify the (dis)advantages of the mechanisms by using information about actual choices under Boston complemented with survey data eliciting students' school preferences.We find that under Boston around 8% of the students apply to another school than their most-preferred school. We compare allocations resulting from Boston with DA with single tie-breaking (one central lottery; DA-STB) and multiple tie-breaking (separate lottery per school; DA-MTB). DA-STB places more students in their top-n schools, for any n, than Boston and results in higher average welfare. We find a trade-off between DA-STB and DA-MTB. DA-STB places more students in their single most-preferred school than DA-MTB, but fewer in their top-n, for n ? 2. Finally, students from disadvantaged backgrounds benefit most from a switch from Boston to any of the DA mechanisms.

Keywords: ex-ante efficiency, strategic behavior, deferred acceptance mechanism, Boston mechanism, school choice, ex-post efficiency

JEL Classification: C83, D47, I20