Fully Bayesian aggregation

• 成果类型: Article
• 署名作者: Dietrich, Franz
• 署名单位: Paris School of Economics; Centre National de la Recherche Scientifique (CNRS)
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2021.105255
• 发表日期: 2021
• 关键词: Preference aggregation under uncertainty; Values aggregation and Harsanyi's Theorem; Belief aggregation and geometric pooling; Bayesian rational group; Static versus dynamic rationality; Spurious unanimity and Pareto conditions

摘要

Can a group be an orthodox rational agent? This requires the group's aggregate preferences to follow expected utility (static rationality) and to evolve by Bayesian updating (dynamic rationality). Group rationality is possible, but the only preference aggregation rules which achieve it (and are minimally Paretian and continuous) are the linear-geometricrules, which combine individual values linearly and combine individual beliefs geometrically. Linear-geometric preference aggregation contrasts with classic linear-linearpreference aggregation, which combines both values and beliefs linearly, but achieves only static rationality. Our characterisation of linear-geometric preference aggregation has two corollaries: a characterisation of linear aggregation of values (Harsanyi's Theorem) and a characterisation of geometric aggregation of beliefs. (c) 2021 Elsevier Inc. All rights reserved.