Agreeing to agree

• 成果类型: Article
• 署名作者: Lehrer, Ehud; Samet, Dov
• 署名单位: Tel Aviv University; Tel Aviv University
• 刊物名称: THEORETICAL ECONOMICS
• ISSN/ISSBN: 1555-7561
• DOI: 10.3982/TE578
• 发表日期: 2011-05-01
• 页码: 269-287
• 关键词: Agreement theorem; common knowledge; common prior; no trade theorem

摘要

Aumann (1976) shows that agents who have a common prior cannot have common knowledge of their posteriors for event E if these posteriors do not coincide. But given an event E, can the agents have posteriors with a common prior such that it is common knowledge that the posteriors for E do coincide? We show that a necessary and sufficient condition for this is the existence of a nonempty finite event F with the following two properties. First, it is common knowledge at F that the agents cannot tell whether E occurred. Second, this still holds true at F, when F itself becomes common knowledge.