The generic possibility of full surplus extraction in models with large type spaces

• 成果类型: Article
• 署名作者: Gizatulina, Alia; Hellwig, Martin
• 署名单位: University of St Gallen; Max Planck Society
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2017.05.009
• 发表日期: 2017
• 页码: 385-416
• 关键词: Mechanism design; Surplus extraction; universal type space; genericity; Correlated information; Strategic continuity

摘要

McAfee and Reny (1992) have given a necessary and sufficient condition for full surplus extraction in naive type spaces with a continuum of payoff types. We generalize their characterization to arbitrary abstract type spaces and to the universal type space and show that in each setting, full surplus extraction is generically possible. We interpret the McAfee Reny condition as a much stronger version of injectiveness of belief functions and prove genericity by arguments similar to those used to prove the classical embedding theorem for continuous functions. Our results can be used to also establish the genericity of common priors that admit full surplus extraction. (C) 2017 Elsevier Inc. All rights reserved.