A theory of school-choice lotteries

• 成果类型: Article
• 署名作者: Kesten, Onur; Uenver, M. Utku
• 署名单位: Carnegie Mellon University; Boston College
• 刊物名称: THEORETICAL ECONOMICS
• ISSN/ISSBN: 1933-6837
• DOI: 10.3982/TE1558
• 发表日期: 2015-05-01
• 页码: 543-595
• 关键词: Matching; school choice; deferred acceptance; STABILITY; ordinal efficiency; market design

摘要

We introduce a new notion of ex ante stability (or fairness) that would be desirable for a school-choice mechanism to satisfy. Our criterion stipulates that a mechanism must be stable based solely on the probabilities that each student will be assigned to different schools, i.e., the assignment must be viewed as stable even before students know which school they will end up going to. This is in contrast to much of the existing literature, which has instead focused on ex post stability, meaning that assignments are deemed stable after students are assigned to schools. Armed with this criterion for evaluating mechanisms, we show that one of the mechanisms that has attracted the most attentiondeferred acceptance with random tie-breakingis not ex ante stable and under some circumstances can lead to ex ante discrimination among some students. We then propose two new mechanisms, which satisfy two notions of ex ante stability we introducea strong one and a weak oneand we show that these mechanisms are optimal within the class of mechanisms that satisfy these respective criteria.