The Effectiveness of Regulations on the Dual-Role Retailer’s Data Use for Sellers

Recent regulatory scrutiny has raised concerns about dominant online retailers’ use of marketplace data to compete with third-party sellers. We examine whether emerging data-use regulations can effectively protect sellers. Our analysis shows that strict restrictions on retailer data access can benefit sellers but may also encourage platforms to respond strategically by changing contract terms, shifting sellers across contractual arrangements, or exploiting regulatory ambiguities. A shared-access policy can offer a more practical compromise by better aligning platform and seller incentives. Importantly, regulatory effectiveness depends on the contractual environment and the platform’s ability to adjust its organizational structure, with these challenges becoming more pronounced under wholesale contracts. Our findings suggest that effective data governance requires more than restricting data access. Regulators should account for contract structure, anticipate strategic platform responses, and establish clearer enforcement conditions that limit opportunities for circumvention and strengthen protection against unfair competitive practices.