讲座题目：Link complementarity and social coordination（联系互补性和社会协调）

主讲人：崔志伟 中国人民大学经济学院

讲座地点：经管院210

讲座时间：2023年11月27日10:00

讲座内容摘要：

We consider a model of social coordination and network formation where agents decide on an action in a coordination game and on whom to form costly links to. We explore the role of link complementarity; that is, active and passive connections are strategic complements, where for a given agent, active connections are links formed by herself, and passive connections are links that other agents form to her. With link complementarity, agents have to deal with both the issue of link coordination and the issue of action coordination. When agents are constrained in the number of links they form, Nash equilibria, including both action-homogenous and action-heterogenous strategy profiles, are characterized by reciprocal sub-networks where an agent forms links with agents who form a link with her. Depending on the precise parameters of the model, risk-dominant or payoff-dominant strategy profiles are stochastically stable. More interestingly, the resulting networks are strongly reciprocal: for almost every agent, the set of agents to whom she forms a link coincides with the set of agents who form a link with her. The notion of strong reciprocity substantially refines the set of reciprocal networks, and offers a prediction for interaction structures.

我们考虑了一个社会协调和网络形成的模型，在这个模型中，代理人在协调博弈中决定行动，并决定与谁建立代价高昂的联系。我们探讨了联系互补性的作用，也就是说，主动联系和被动联系是一种战略互补，对于某个代理人来说，主动联系是由她自己形成的联系，而被动联系则是其他代理人与她形成的联系。在联系互补的情况下，代理人既要处理联系协调问题，又要处理行动协调问题。当代理人在建立联系的数量上受到限制时，纳什均衡，包括行动同质和行动异质策略组合，其特征是相互的子网络，其中代理人和与她建立联系的代理人形成联系。根据模型的精确参数，风险主导型或报酬主导型策略组合是随机稳定的。更有趣的是，由此产生的网络是强相互的：对几乎每个代理人来说，她建立联系的代理人集合和与她建立联系的代理人集合是重合的。强相互的概念大大完善了相互网络的集合，并为互动结构提供了预测。

主讲人学术简介：

崔志伟，中国人民大学经济学院副教授。主要研究领域及兴趣为网络博弈理论及应用、博弈学习理论及应用等。主持多项国家自然科学基金项目，研究成果发表于Journal of Economic Theory、Games and Economic Behavior、Journal of Economic Behavior and Organization、Journal of Economic Dynamics and Control、Journal of Mathematical Economics等国际经济学权威期刊，以及《管理评论》、《运筹与管理》等管理类CSSCI权威期刊。