As technology and interconnectivity have continued to flourish, so too has an important and complex form of enterprise: the platform. Services like Uber, Google Search, Hulu, and American Express cater to distinct but deeply-interdependent “sides” of customers that derive value or revenues...

We study platforms competing in commissions on revenues of sellers engaged in monopolistic competition, as the app providers on the app stores of iPhones and Android devices. Free entry of sellers on each platform generates multihoming superstars and a long tail of singlehoming sellers....

This paper examines the effect of private label sold by one of two retailers (the “chain store”) on wholesale prices in the intermediate goods market. Under sym- metric retail costs, the chain store can make the wholesale price lower than its rival (the “local store”) when the private...

We consider a dynamic platform competition in a market with network externalities. The incumbent platform enjoys a focal position such that consumers expect other consumers to join it, while the entrant platform may enjoy a quality advantage. We examine the effect of an antitrust policy that...

This chapter sets out the principles and emerging practice governing cartel damages in the EU and UK. It identifies the types of damages available; the issue surrounding causation, pass-on, volume effects, and mitigation; and the methods that have been be used to estimate overcharges, volume...

Amazon acts as both a platform operator and seller on its platform, designing rich fee policies and offering some products direct to consumers. This flexibility may improve welfare by increasing fee discrimination and reducing double marginalization, but may decrease welfare due to incentives to...

This paper analyzes the effects of tying arrangements on market competition and social welfare in two-sided markets when economic agents can engage in multi-homing; that is, they can participate in multiple platforms in order to reap maximal network benefits. The model shows that tying induces...

This paper investigates how different damage rules in patent infringement cases shape competition when intellectual property rights are probabilistic. I develop a simple model of oligopolistic competition to compare two main liability doctrines that have been used in the US to assess...

This paper studies optimal sport league size. League expansion lowers average player quality, reducing fans' utility in inframarginal locations, while fan utility in new locations rises. Welfare analyses of such expansions must compare these two effects. Using a model where fan demand depends on...