Majority rule in the absence of a majority

• 成果类型: Article
• 署名作者: Nehring, Klaus; Pivato, Marcus
• 署名单位: University of California System; University of California Davis; CY Cergy Paris Universite
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2019.05.006
• 发表日期: 2019
• 页码: 213-257
• 关键词: Judgment aggregation; DISAGREEMENT; voting; Median rule; Supermajority efficiency

摘要

Which is the best, impartially most plausible consensus view to serve as the basis of democratic group decision when voters disagree? Assuming that the judgment aggregation problem can be framed as a matter of judging a set of binary propositions (issues), we develop a multi-issue majoritarian approach based on the criterion of supermajority efficiency (SME). SME reflects the idea that smaller supermajorities must yield to larger supermajorities so as to obtain better supported, more plausible group judgments. As it is based on a partial ordering, SME delivers unique outcomes only in special cases. In general, one needs to make cardinal, not just ordinal, tradeoffs between different supermajorities. Hence we axiomatically characterize the class of additive majority rules, whose (generically unique) outcome can be interpreted as the on balance most plausible consensus judgment. (C) 2019 Published by Elsevier Inc.