Defining the gatekeeper concept and its application criteria in digital markets from a competition law perspective

Developments in market structures and the conduct of undertakings frequently necessitate legislative reforms, leading to the adoption of new laws or amendments to existing ones. However, it is rare that the situation created by the economic structure of a market and especially the concerns created by the practices of undertakings in the relevant market almost radically change the application and legislation of a branch of law. The current situation in digital markets and the need to intervene in this situation has added a new intervention tool to the Competition Law's mechanism of successive (ex-post) supervision and sanctioning. With this new control mechanism, which is shaped as ex-ante intervention, administrative authorities aim to address anti-competitive concerns in digital markets by making certain undertakings apply the new rules of conduct added to the legislation. One of the most important consequences of these new regulations is the emergence of the concept of "Gatekeeper. "Gatekeeper" refers to the undertakings that have the power to control the access of one group of users to another group of users in the context of the platform economy. Gatekeeper undertakings constitute the subject of the ex-ante supervision mechanism to be conducted by competition authorities in digital markets. The main topics of our study are the evaluation of the gatekeeper criteria used to classify and identify the undertakings to be subject to ex ante supervision from the perspective of the legal discipline, the application of qualitative and quantitative criteria, and how the ideal criteria should be shaped.