How Search Engine Impacts Market Structure: Empirical Evidence from a Multivendor Darknet Market
利用暗网交易平台数据，研究了跨网站搜索引擎GRAMS的引入对市场结构的影响，发现其提升了整体市场表现，但加剧了市场集中度，领先卖家和热门产品获益更多。
Despite the public’s familiarity with search engines, little existing research empirically investigates the impact of such a search-cost-reduction tool on online market structure. Knowledge scarcity of this question can mainly be attributed to the challenge of accessing detailed data from a cross-website search engine. Using data from the online illegal transaction platform, the Darknet markets, we manage to empirically evaluate the influence of a cross-website search engine (i.e., GRAMS) on the market structure at the vendor and product category levels. The results show that, although the search engine’s entry enhances the overall market performance, the benefit is more significant among leading vendors and popular products, contributing to a more concentrated market. Additional analyses provide empirical evidence that the trustworthiness and the scale-up ability of leading vendors can be the underlying mechanisms for the increased market concentration after the introduction of search engines into Darknet markets. Our study not only contributes to the literature on the dynamics of sales distribution in a multiple-vendor e-commerce market but also provides insights into understanding the operating dynamics of the Darknet markets, which can be helpful for law enforcement policymaking. This paper was accepted by D. J. Wu, information systems. Funding: D. Qiao acknowledges financial support from the Singapore Ministry of Education [Tier 1 Research Grant A-8001813-00-00]. S. He acknowledges financial support from the University of Florida, Warrington College of Business Summer 2022 Research Award. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2022.04133 .