POSITIVELY RESPONSIVE COLLECTIVE CHOICE RULES AND MAJORITY RULE: A GENERALIZATION OF MAY'S THEOREM TO MANY ALTERNATIVES

• 成果类型: Article
• 署名作者: Horan, Sean; Osborne, Martin J.; Sanver, M. Remzi
• 署名单位: Universite de Montreal; Universite de Montreal; University of Toronto; Universite PSL; Universite Paris-Dauphine; Centre National de la Recherche Scientifique (CNRS)
• 刊物名称: INTERNATIONAL ECONOMIC REVIEW
• ISSN/ISSBN: 0020-6598
• DOI: 10.1111/iere.12394
• 发表日期: 2019
• 页码: 1489-1504
• 关键词: impossibility theorems; rationality; Consistency

摘要

May's theorem shows that if the set of alternatives contains two members, an anonymous and neutral collective choice rule is positively responsive if and only if it is majority rule. We show that if the set of alternatives contains three or more alternatives only the rule that assigns to every problem its strict Condorcet winner satisfies the three conditions plus Nash's version of independence of irrelevant alternatives for the domain of problems that have strict Condorcet winners. We show also that no rule satisfies the four conditions for domains that are more than slightly larger.