Preference Formation and Peer Effects in University Admission: The Further Deferred Acceptance

就研究如何改善真实的生活实践而言，市场设计一直是经济学中最成功的领域之一。2012年诺贝尔经济学奖授予阿尔文·罗斯和劳埃德·沙普利，以表彰他们“稳定配置理论和市场设计实践”。然而，许多尚未解决的研究问题和实际问题仍然存在。本研究旨在通过关注两个开放性问题来加深我们对大学入学市场设计的理解。首先，通常假设学生可以免费对所有大学进行偏好排名。其次，文献大多不考虑外部性，如同行效应。不幸的是，这两个假设在真实的应用中不太可能得到满足。例如，学生通常从大量选项中进行选择，而他们对这些选项的信息有限，因此很难制定完整的偏好排名。此外，学生可能更喜欢在他们的朋友被大学录取的地方附近学习。德国最近引入的一种新机制解决了标准假设不成立时可能出现的问题。我们的项目研究了这种机制，它是延迟接受（DA）机制的变体（Gale和Shapley，1962）。由于其理想的理论属性，如稳定性和防策略性，DA一直处于市场设计的中心，并已被许多教育机构采用，如波士顿，纽约市和巴黎的学校选择。与DA相比，德国的机制有两个重要特点：第一，该系统中的学生“申请”一组大学，只有在大学发出第一轮录取通知书后才被要求对它们进行排名。第二，学生可能会收到多个第一轮录取通知书，并可以决定保留哪一个。与提名评审委员会比较，评审排名和接纳/拒绝首轮申请的时间会进一步延迟。因此，我们称之为进一步延迟接受（FDA）机制。我们建立了一个模型来说明，FDA主导DA在学生福利方面，如果偏好的形成是昂贵的和/或同伴效应存在。这两个成分的模型是非标准的文献。为了实证检验这些假设，我们使用调查，行政和实验数据。FDA相对于DA的表现也将通过反事实分析进行定量评估，即根据估计的偏好模拟两种机制下的结果。本项目将研究当申请人不确定自己的偏好以及偏好受到同行影响时的市场设计解决方案。我们的项目将使用理论和数据提供FDA主导DA的条件的证据。鉴于从DA转换到FDA的成本较低，这在许多现实生活中可能是一种选择。

Market design has been one of the most successful fields of economics in terms of how research has improved practices in real life. As a recognition, the 2012 Nobel Prize in Economics was awarded to Alvin Roth and Lloyd Shapley "for the theory of stable allocations and the practice of market design". However, many unresolved research questions and practical problems remain. This research aims to advance our understanding of market design for university admission by focusing on two open questions. First, it is typically assumed that students can form a preference ranking of all universities at no cost. Second, the literature mostly does not allow for externalities such as peer effects. Unfortunately, both assumptions are unlikely to be satisfied in real applications. For example, students usually choose from a large set of options about which they have limited information, and thus have difficulties to formulate a full preference ranking. Also, students may prefer to study close to where their friends are admitted to university.A new mechanism that was recently introduced in Germany addresses the problems that can arise when the standard assumptions do not hold. Our project investigates this mechanism which is a variant of the Deferred-Acceptance (DA) mechanism (Gale and Shapley, 1962). Due to its desirable theoretical properties such as stability and strategy-proofness, the DA has been at the very center of market design, and it has been adopted in numerous educational settings such as school choice in Boston, New York City, and Paris. In contrast to the DA, the German mechanism has two important features: First, students in the system "apply to" a set of universities and are only required to rank them after universities make first-round offers. Second, students may receive multiple first-round offers and can decide which one to keep. Compared with the DA, the ranking decision and the acceptance/rejection of first-round offers are further deferred. Hence, we call it the Further-Deferred-Acceptance (FDA) mechanism. We build a model to illustrate that the FDA dominates the DA in terms of student welfare if preference formation is costly and/or peer effects exist. Both ingredients of the model are non-standard in the literature. To empirically test these assumptions, we use survey, administrative, and experimental data. The performance of the FDA relative to the DA will also be evaluated quantitatively by counterfactual analyses, i.e. by simulating outcomes under both mechanisms based on estimated preferences.This project will investigate a market design solution when applicants are uncertain about their preferences and when preferences are affected by peers. Our project will provide evidence on the conditions under which the FDA dominates the DA, using both theory and data. Given the low cost of switching from the DA to the FDA, this can be an option in many real-life contexts.