On the tradeoff between efficiency and strategyproofness

• 成果类型: Article
• 署名作者: Aziz, Haris; Brandl, Florian; Brandt, Felix; Brill, Markus
• 署名单位: Commonwealth Scientific & Industrial Research Organisation (CSIRO); CSIRO Data61; University of New South Wales Sydney; Technical University of Munich; Technical University of Berlin
• 刊物名称: GAMES AND ECONOMIC BEHAVIOR
• ISSN/ISSBN: 0899-8256
• DOI: 10.1016/j.geb.2018.03.005
• 发表日期: 2018
• 页码: 1-18
• 关键词: strategyproofness; EFFICIENCY; stochastic dominance; random serial dictatorship; maximal lotteries

摘要

We study social decision schemes (SDSs), i.e., functions that map a collection of individual preferences over alternatives to a lottery over the alternatives. Depending on how preferences over alternatives are extended to preferences over lotteries, there are varying degrees of efficiency and strategyproofness. In this paper, we consider four such preference extensions: stochastic dominance (SD), a strengthening of SD based on pairwise comparisons (PC), a weakening of SD called bilinear dominance (BD), and an even weaker extension based on Savage's sure-thing principle (ST). While random serial dictatorships are PC-strategyproof, they only satisfy ex post efficiency. On the other hand, we show that strict maximal lotteries are PC-efficient and ST-strategyproof. We also prove the incompatibility of (i) PC-efficiency and PC-strategyproofness for anonymous and neutral SDSs, (ii) ex post efficiency and BD-strategyproofness for pairwise SDSs, and (iii) ex post efficiency and BD-group-strategyproofness for anonymous and neutral SDSs. (C) 2018 Elsevier Inc. All rights reserved.