On guarantees, vetoes, and random dictators

• 成果类型: Article
• 署名作者: Bogomolnaia, Anna; Holzman, Ron; Moulin, Herve
• 署名单位: University of Glasgow; Technion Israel Institute of Technology; University of Glasgow
• 刊物名称: THEORETICAL ECONOMICS
• ISSN/ISSBN: 1933-6837
• DOI: 10.3982/TE4832
• 发表日期: 2023-01-01
• 页码: 97-127
• 关键词: Worst case; guarantees; voting by veto; random dictator; D63; D71

摘要

A mechanism guarantees a certain welfare level to its agents, if each of them can secure that level against unanimously adversarial others. How high can such a guarantee be, and what type of mechanism achieves it?In the n-person probabilistic voting/bargaining model with p deterministic outcomes a guarantee takes the form of a probability distribution over the ranks from 1 to p. If n >= p, the uniform lottery is shown to be the only maximal (unimprovable) guarantee. If n < p, combining (variants of) the familiar random dictator and voting by veto mechanisms yields a large family of maximal guarantees: it is exhaustive if n = 2 and almost so if p <= 2n.Voting rules a la Condorcet or Borda, even in probabilistic form, are ruled out by our worst case viewpoint.