Core stability and strategy-proofness in hedonic coalition formation problems with friend-oriented preferences

• 成果类型: Article
• 署名作者: Klaus, Bettina; Klijn, Flip; Ozbilen, Seckin
• 署名单位: University of Lausanne; Autonomous University of Barcelona; Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Institut d'Analisi Economica (IAE); Autonomous University of Barcelona; Ozyegin University
• 刊物名称: GAMES AND ECONOMIC BEHAVIOR
• ISSN/ISSBN: 0899-8256
• DOI: 10.1016/j.geb.2025.08.007
• 发表日期: 2025
• 页码: 16-52
• 关键词: Hedonic coalition formation; (Strict) core stability; (Group) strategy-proofness; Strongly connected components

摘要

We study hedonic coalition formation problems with friend-oriented preferences; that is, each agent has preferences over his coalitions based on a partition of the set of agents, except himself, into friends and enemies such that (E) adding an enemy makes him strictly worse off and (F) adding a friend together with a set of enemies makes him strictly better off. Friend-oriented preferences induce a so-called friendship graph where vertices are agents and directed edges point to friends. We show that the partition associated with the strongly connected components (SCC) of the friendship graph is in the strict core. We then prove that the SCC mechanism, which assigns the SCC partition to each hedonic coalition formation problem with friend-oriented preferences, satisfies a strong group incentive compatibility property: group strategy-proofness. Our main result is that on any rich subdomain of friend-oriented preferences, the SCC mechanism is the only mechanism that satisfies core stability and strategy-proofness.