Top monotonicity: A common root for single peakedness, single crossing and the median voter result

• 成果类型: Article
• 署名作者: Barbera, Salvador; Moreno, Bernardo
• 署名单位: Autonomous University of Barcelona; Universidad de Malaga; Universidad de Malaga
• 刊物名称: GAMES AND ECONOMIC BEHAVIOR
• ISSN/ISSBN: 0899-8256
• DOI: 10.1016/j.geb.2011.02.004
• 发表日期: 2011
• 页码: 345-359
• 关键词: Single peaked; Single crossing and intermediate preferences; Majority (Condorcet) winners

摘要

When members of a voting body exhibit single peaked preferences, pair-wise majority voting equilibria (Condorcet winners) always exist. Moreover, they coincide with the median(s) of the voters' most preferred alternatives. This important fact is known as the median voter result. Variants of it also apply when single-peakedness fails, but preferences verify other domain restrictions, such as single-crossing, intermediateness or order restriction. Austen-Smith and Banks (1999) also proved that the result holds under single-peakedness, for a wide class of voting rules that includes the majority rule as a special case, and conveniently redefined versions of a median. We extend and unify previous results. We propose a new domain condition, called top monotonicity, which encompasses all previous domains restrictions, allows for new ones and preserves a version of the median voter result for a large class of voting rules. We also show that top monotonicity arises in interesting economic environments. (C) 2011 Elsevier Inc. All rights reserved.