Mean Field Equilibrium: Uniqueness, Existence, and Statics

• 成果类型: Article
• 署名作者: Light, Bar; Weintraub, Y. Gabriel
• 署名单位: Stanford University
• 刊物名称: OPERATIONS RESEARCH
• ISSN/ISSBN: 0030-364X
• DOI: 10.1287/opre.2020.2090
• 发表日期: 2022
• 页码: 585-605
• 关键词: perfect industry dynamics; games; COMPETITION; reputation; systems

摘要

The standard solution concept for stochastic games is Markov perfect equi-librium; however, its computation becomes intractable as the number of players increases. Instead, we consider mean field equilibrium (MFE), which has been popularized in recent literature. MFE takes advantage of averaging effects in models with a large number of players. We make three main contributions. First, our main result provides conditions that ensure the uniqueness of an MFE. We believe this uniqueness result is the first of its nature in the class of models we study. Second, we generalize previous MFE existence results. Third, we provide general comparative statics results. We apply our results to dynamic oligopoly models and to heterogeneous agent macroeconomic models commonly used in previous work in economics and operations.