We show that there is no consistent Pareto improvement over any stable mechanism. We introduce the following weakly consistent Pareto improvement ( over the student-optimal stable matching ) requirement: whenever a set of students, each of whom is assigned to a school that is underdemanded at the student-optimal stable matching, is removed with their assigned seats, then the assignments of the remaining students do not change. Our main result is that the efficiency-adjusted deferred acceptance mechanism (Kesten in Q J Econ 125(3):1297–1348, 2010 ) is the unique weakly consistent Pareto improvement over the student-optimal stable mechanism.

中文翻译：

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帕累托对学生最优稳定机制的一致改进

我们表明，在任何稳定机制上都没有一致的帕累托改进。我们引入以下弱一致的帕累托改进（超过学生最佳稳定匹配）的要求：每当一组学生（每个学生分配到在学生最佳稳定匹配方面需求不足的学校）时，都将其分配的席位移除，则其余学生的作业不会更改。我们的主要结果是，效率调整后的递延接受机制（Kesten in QJ Econ 125（3）：1297-1348，2010）是对学生最优稳定机制的唯一弱一致性帕累托改进。