Public Responsibility and Public Law Regulation of Platform Operators : A Focus on the Control of Market Dominance and the Protection of Users

This study focuses on the quasi-public functions and informational control power of online platform operators in the digital economy, aiming to justify their public responsibility based on constitutional and administrative law principles. Recognizing the limitations of existing civil and economic law regulations in addressing structural problems such as abuse of market dominance, information asymmetry, and consumer rights infringement, this paper proposes the introduction of a public law regulatory framework. Specifically, the study presents institutional improvement measures, including the public service trustee theory, protection of informational fundamental rights, public law-based information disclosure obligations, algorithmic transparency obligations, the establishment of a digital supervisory authority, and the institutionalization of co-regulation models. Comparative analysis of foreign legislative examples - such as the EU’s Digital Markets Act(DMA) and Digital Services Act(DSA), Japan’s Transparency Act, and regulatory cases from the U.S. Federal Trade Commission(FTC) - demonstrates both the feasibility and normative justification of public law regulation. By presenting a creative and innovative legal perspective regarding the public status of platform operators and the transition of their legal responsibilities, this study offers a theoretical contribution to the construction of a public law regulatory system and explores its potential for practical implementation. Ultimately, this research proposes a new regulatory paradigm of digital publicness necessary for the digital platform era, contributing both academic value and policy relevance.