关键词: 竞价排名, 信息不对称, 搜索引擎平台, 信息匹配效率

Abstract: Focusing on the phenomenon that consumers rely on the keyword retrieval of search engine platform to make purchase decision, this paper introduces consumer search behavior into the bidding mechanism of search engine platform and construct a game model with search engine platform, seller and consumer, to investigate the information matching efficiency of the bidding mechanism of search engine platform under information asymmetry. Based on that, we investigate the theoretical mechanism of product quality as a signal to improve the information matching efficiency of bidding mechanism. Our research findings show that, under information asymmetry and without the signal of product quality, the equilibrium of the bidding mechanism fails to match the purchase decisions of consumers at all, resulting in double losses of consumer welfare due to the adverse selection of sellers. After the signal of product quality is implanted, the search engine platform can improve the matching degree between the equilibrium of the bidding mechanism and the consumer purchase decisions by identifying the product quality signal of sellers, and then partially improve the information matching efficiency of the bidding mechanism.

Key words: bidding ranking, information asymmetry, search engine platform, information matching efficiency