{"title":"Ex-Ante Fairness in the Boston and Serial Dictatorship Mechanisms Under Pre-Exam and Post-Exam Preference Submission","authors":"J. Lien, Jie Zheng, Xiaohan Zhong","doi":"10.2139/ssrn.2714677","DOIUrl":null,"url":null,"abstract":"In a school choice mechanism, school priorities are often based on student exam scores, by which student true ability may not be perfectly revealed. An ex-post fair matching mechanism (for example, Serial Dictatorship) can be undesirable in that it is not ex-ante fair: it may not match students with higher abilities to better schools, although it always matches students with higher scores to better schools. In this paper we consider a potential way of improving ex-ante fairness – a Boston mechanism with the requirement that students submit their preferences before the exam score is realized (the “pre-BOS mechanism”). This mechanism is more likely to achieve complete ex-ante fairness, in that students with higher ability are always matched with better schools. However, the other mechanisms (pre-/post-SD and post-BOS) can always implement stochastic ex-ante fairness (students with higher ability having higher probability of admission to better schools), while pre-BOS may not.","PeriodicalId":393761,"journal":{"name":"ERN: Other Game Theory & Bargaining Theory (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2016-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"34","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ERN: Other Game Theory & Bargaining Theory (Topic)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2139/ssrn.2714677","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 34
Abstract
In a school choice mechanism, school priorities are often based on student exam scores, by which student true ability may not be perfectly revealed. An ex-post fair matching mechanism (for example, Serial Dictatorship) can be undesirable in that it is not ex-ante fair: it may not match students with higher abilities to better schools, although it always matches students with higher scores to better schools. In this paper we consider a potential way of improving ex-ante fairness – a Boston mechanism with the requirement that students submit their preferences before the exam score is realized (the “pre-BOS mechanism”). This mechanism is more likely to achieve complete ex-ante fairness, in that students with higher ability are always matched with better schools. However, the other mechanisms (pre-/post-SD and post-BOS) can always implement stochastic ex-ante fairness (students with higher ability having higher probability of admission to better schools), while pre-BOS may not.