Platform markets, dominance issues and single- and multi-homing of merchants: A real or hypothetical choice?

This article considers the implications of restricting the ability of business users to interact with a plurality of platforms for competition between platforms and between the merchants themselves. After examining the economic implications of the merchants’ choice of single- versus multi-homing, the article will analyse the legality of two practices that can restrict, if not altogether deny, the ability of merchants to choose whether to use one or a plurality of platforms in light of the EU Competition rules, namely exclusivity clauses and across platforms parity agreements. It will be argued that due to the features of platform markets, the ability of merchants to multi-home should be preserved so as to ensure that these markets remain open and competitive and that the incentive for new intermediaries to continue innovating in the way they provide their services.