Robustly optimal voting rule

• 成果类型: Article
• 署名作者: Kiguchi, Noriaki; Noguchi, Shinpei; Takahashi, Yuta
• 署名单位: Tokyo Keizai University; Hitotsubashi University; University of Osaka
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2026.106219
• 发表日期: 2026
• 关键词: Strategy-proofness; expected utility; mechanism design; ambiguity; axioms; VALUES

摘要

We examine optimal strategy-proof voting mechanisms in environments where the designer lacks precise information about the probability distribution of individual utility profiles. This uncertainty over the true distribution is represented by a set of multiple distributions, and the designer evaluates mechanisms using either the worst-case utility sum or worst-case regret. Departing from the existing literature, we do not assume that utility functions are single-peaked or that the set of possible utility functions is maximally rich. In this setting, we show that the median voter rule is the unique optimal mechanism under both criteria. Our result provides a new justification for this well-known mechanism from a welfare perspective.