Michael Katz and Jonathan Sallet ‘Multisided Platforms and Antitrust Enforcement’ (2018) Yale Law Journal 2142

This paper,  available here, looks at two questions regarding competition enforcement in platform markets: (i) how should one account for the distinct characteristics of platforms when defining an antitrust market; and (ii) how, if at all, should one weigh user groups’ gains and losses on different sides of a platform against one another. In short, the authors argue that enforcers and courts should use a multiple-markets approach to multisided platforms, in which different groups of users on different sides of a platform belong in different product markets. This approach allows one to account for cross-market network effects without collapsing all platform users into a single product market. They further argue that enforcers should consider the price structure of a platform, and not simply its net price, when assessing competitive effects. This justifies the use of a separate-effects analysis, according to which anticompetitive conduct harming users on one side of a platform cannot be justified just because that harm funds benefits for users…

Lapo Filistrucchi ‘Two-sided v Complementary Products’ (2018) CPI Antitrust September Chronicle

This paper, which can be found here, It aims to clarify whether and to what extent two-sided platforms are different from platforms selling complementary products. It also seeks to explain why the distinction matters for the purposes of competition assessments of firms’ behaviour. The paper is structured as follows: A first section explains why firms operating in two-sided markets are different from firms selling complementary products. According to the economic literature, a two-sided platform is a firm that sells two different products or services to two groups of consumers, where the demand from one group of consumers depends on the demand from the other group and, potentially, vice versa. In other words, demand is affected by indirect network effects (i.e. consumers’ willingness to pay for a product depends on the number of consumers (or the quantity bought) of another product). A platform internalizes these indirect network effects. There are differences between platforms and firms selling complements. A first difference is that, in…

Daniel Mandrescu ‘Applying (EU) Competition Law to Online Platforms: Reflections on the Definition of the Relevant Market(s)’ (2018) World Competition 41(3) 453

Online platforms cater their services to at least two separate customer groups by facilitating an interaction. Accordingly, when assessing the market power of an online platform, it is essential to establish whether those customer groups are part of a single relevant market or multiple relevant markets. The purpose of this article, available here, is to provide practical guidance on the market definition process for online platforms in light of their distinctive characteristics. It does so through three sections: The first section shortly discusses the importance of the market definition for the application of Article 102 TFEU in practice. Findings of dominance rely on an adequate measurement of economic market power. Whether economic market power amounts to legal dominance is a determination that depends on a properly defined relevant market. Market definition is also required for evaluating any possible efficiency arguments that would justify the prima facie anticompetitive practices of the concerned undertaking. The second section develops an approach to market definition…