ECONOMIC MECHANISMS OF STATE REGULATION OF DIGITAL OLIGOPOLIES IN EU COUNTRIES

This article examines the nature and specificity of digital oligopolies in the European Union, their economic characteristics, and the sources of their market power. It outlines the evolution of EU regulatory policy – from ex-post (retrospec tive) to ex-ante (preventive) approaches – with particular attention to the implementation of the Digital Markets Act (DMA). The study analyses the lobbying expenditures of EU digital platforms, the degree of market concentration in the EU digital ecosystem, and the resulting need for differentiated state regulation of platform services within the Union. The article proposes a Herfindahl–Hirschman Index (HHI) scale suitable for modelling user behaviour, assessing economies of scale, and evaluating platform-to-platform interactions, as well as an analytical system of criteria for clustering digital platforms by market structure type, integrating both economic and structural parameters.