When are signals complements or substitutes?

• 成果类型: Article
• 署名作者: Boergers, Tilman; Hernando-Veciana, Angel; Kraehmer, Daniel
• 署名单位: University of Michigan System; University of Michigan; Universidad Carlos III de Madrid; University of Bonn
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2012.12.012
• 发表日期: 2013
• 页码: 165-195
• 关键词: Complementarity; substitutability; value of information; Blackwell ordering

摘要

The paper introduces a notion of complementarity (substitutability) of two signals which requires that in all decision problems each signal becomes more (less) valuable when the other signal becomes available. We provide a general characterization which relates complementarity and substitutability to a Blackwell comparison of two auxiliary signals. In a setting with a binary state space and binary signals, we find an explicit characterization that permits an intuitive interpretation of complementarity and substitutability. We demonstrate how these conditions extend to more general settings. We also illustrate the implications of our concepts for three economic applications: information disclosure in auctions, information aggregation through voting, and polarization of beliefs. (C) 2012 Elsevier Inc. All rights reserved.