Nontruthful Position Auctions Are More Robust to Misspecification

• 成果类型: Article
• 署名作者: Dutting, Paul; Fischer, Felix; Parkes, David C.
• 署名单位: Alphabet Inc.; Google Incorporated; University of London; Queen Mary University London; Harvard University
• 刊物名称: MATHEMATICS OF OPERATIONS RESEARCH
• ISSN/ISSBN: 0364-765X
• 发表日期: 2024
• 页码: 901-927
• 关键词: prophet inequalities; Online algorithms; stop rule; optimization; mechanisms; DECISION; supremum; maximum

摘要

We consider the classical model of sponsored search due to Edelman et al. and Varian and examine how robust standard position auctions are to a misspecification of the position-dependent quality factors used by this model. We show that under both complete and incomplete information a nontruthful position auction admits an efficient equilibrium for a strictly broader range of parameter values than the Vickrey-Clarke-Groves (VCG) mechanism, which would be truthful if the parameters were specified correctly. Our result for complete information concerns the generalized second-price (GSP) mechanism and is driven by a detailed understanding of the Nash equilibrium polytopes of the VCG mechanism and the GSP mechanism. Our result for incomplete information concerns the generalized first-price (GFP) mechanism and uses a surprising connection between the unique candidate equilibrium bidding functions of the VCG mechanism and the GFP mechanism.