Rethinking Modes of Market Definition for multi-Sided Platforms

The relevant market definition based on SSNIP test is a starting point for the analysis concerning abuse of market dominant position. In other words, abuse of market dominant position presupposes that there is market dominant power in the market and market dominant power should be inferred from high market share, and in order to calculate market share, relevant market should be defined, and the relevant market should be defined by means of the SSNIP test reflecting the substitutability of demand or supply. Meanwhile, a market definition for multi-sided platforms is complex and incoherent due to particular features of multi-sided platforms. In this regard, some modified tools of market definition for multi-sided platforms are suggested with related Korean cases.