主 题：Balancing Efficiency and Equality in Vehicle Licenses Allocation (兼顾公平和效率的车牌分配机制)
主讲人：陈洲 博士 上海财经大学信息管理与工程学院
主持人：陈梦妙 博士 上海对外经贸大学国际经贸学院物流管理系
时 间：2021年10月28日（星期四）10:00—11:30
地 点：上海对外经贸大学 博识楼113
主讲人简介：陈洲，香港科技大学博士，上海财经大学和香港科技大学博士后。研究方向包括运筹学，博弈论，算法设计及其在网络经济，收益管理，市场运营，共享经济中的应用。在Discrete Applied Mathematics，Journal of Combinatorial Optimization和IEEE Transactions on Cloud Computing（SCI 一区）等国际权威杂志上发表论文多篇。
摘要：在目前汽车尾气带来的环境问题和城市交通日益拥堵的大环境下，越来越多的国家和地区已经开始采取限制车牌数量的政策。在这些地方，政府对车牌进行限额分配。目前，车牌的分配因地而异，已经实施的机制有拍卖、摇号、保留价格摇号以及同时拍卖和摇号，不同的机制对公平和效率有不同的侧重。我们希望设计一个最佳的、简单的机制来最优地平衡效率和公平。我们首先提出了一个两组的统一框架，该框架在实践中包括或优于所有现有的机制。在这个框架下，我们证明了只要参与者的价值分布是任一常用分布，最优机制总是先拍卖后摇号。这种最佳的分配规则仅取决于车牌总数和参与者总数。最后我们将二组的框架扩展为通用的多组框架，并且证明了两组的最优已经接近理论的多组最优。并且两组最优由于其激励相容性和结构的简单，在实践中也易于实施。我们的工作为车牌分配问题提供了一种简单易行且有效的工具，并且保证了在一定公平水平的约束下最大限度地提高社会效率。
Abstract: Many big cities have begun to adopt policies limiting the number of vehicle licenses because of traffic and air quality concerns. In these cities, every one or two months a limited number of new vehicle licenses are distributed amongst a very large number of potential car buyers. Currently, the allocation mechanisms differ from city to city. Several mechanisms have been developed and implemented, such as auctions, lotteries, lotteries with reserved price, and simultaneous auctions and lotteries. In this work, we attempt to design an optimal, simple mechanism to balance efficiency and equality. We first propose a framework using a unified two-group mechanism that either includes or outperforms all existing mechanisms in practice. Further, the unified framework is also easy to implement in practice due to its truthfulness and simple structure. Using this framework, assuming the players' private values are drawn independently from a common distribution, we prove the optimal mechanism always consists of a sequential auction and lottery. In addition, the optimal allocation rule depends only on the total number of players and the total number of licenses for all commonly used distributions. We then extend the two-group framework to a general multi-group framework. The experimental results show us that the optimal two-group mechanism is the best practical choice. Consequently, our work provides an effective tool for social planners to design truthful mechanisms to maximize social efficiency for any level of equality. We also discuss possible applications of our results to resource allocation in other settings.