Making school choice lotteries transparent

TL;DR

This paper argues that revealing school choice lottery outcomes to students before they submit preferences improves decision-making, supported by models and laboratory experiments.

Contribution

It introduces the idea of transparent lotteries in school choice and demonstrates their benefits through theoretical models and experimental validation.

Findings

Revealing lotteries reduces student uncertainty.

Transparency leads to more informed preference submissions.

Laboratory experiments support the theoretical predictions.

Abstract

Lotteries are commonly employed in school choice to fairly resolve priority ties; however, current practices typically keep students uninformed about their lottery outcomes at the time of preference submission. This paper advocates for revealing lottery information to students beforehand. When preference lists are constrained in length, which is a common feature in real-world systems, such disclosure reduces uncertainty and enables students to make more informed decisions. We demonstrate the benefits of lottery revelation through two stylized models. Theoretical predictions are supported by laboratory experiments.