讲座题目：A Taxonomy of Non-dictatorial Domains
内容摘要：A preference domain is called a non-dictatorial domain if it allows the design of unanimous social choice functions (henceforth, rules) that are non-dictatorial and strategy-proof; otherwise it is called a dictatorial domain. We propose a richness condition on the domain and establish that the unique seconds property (introduced by Aswal, Chatterji, and Sen (2003)) separates non-dictatorial domains from dictatorial domains. The principal contribution of the paper is the subsequent exhaustive classification of all rich non-dictatorial domains based on a simple property of two-voter rules called invariance. The preference domains that constitute the classification are semi-single-peaked domains (introduced by Chatterji, Sanver, and Sen (2013)) and semi-hybrid domains (introduced here) which are two appropriate weakenings of single-peaked domains and which, importantly, are shown to allow strategy-proof rules to depend on non-peak information of voters’preferences. As a refinement of the classification, single-peaked domains and hybrid domains emerge as the only rich preference domains that force strategy-proof rules to be determined completely by the peaks of voters’preferences.
主讲人简介：曾华夏，上海财经大学经济学院副教授。新加坡管理大学经济学博士。主要研究领域为机制设计，微观经济理论等。有多篇论文发表于Theoretical Economics，Journal of Economic Theory，Games and Economic Behavior等国际期刊。