Something old and important is lost sight of in a case like Ohio v. American Express, the Supreme Court's recent adoption of "platform" or "two-sided market" theory in American antitrust, and in theoretical efforts like the one on which it is based. A rarely discussed idea built in to American...

This paper investigates the effects on tacit collusion of increased market transparency on the consumer side of a market in a differentiated Hotelling duopoly. Increasing market transparency increases the benefits to a firm from underbutting the collusive price. It also decreases the punishment...

Digitale Großkonzerne wie Facebook, Google & Co. stellen die Wettbewerbsinstitutionen vor neue Herausforderungen. Mithilfe der Charakteristiken von Plattformmärkten können sie ihre Macht und Verhandlungsstärke zunehmend verfestigen und darüber hinaus marktübergreifende digitale Ökosysteme...

This essay discusses two immanent challenges for competition policy in online e-commerce markets: the platform character and the role of personalized data. Both phenomena are briefly described from an economic perspective (section 2 and 3) with a focus on how they affect and change competition...

Digitale Großkonzerne wie Facebook, Google & Co. stellen die Wettbewerbsinstitutionen vor neue Herausforderungen. Mithilfe der Charakteristiken von Plattformmärkten können sie ihre Macht und Verhandlungsstärke zunehmend verfestigen und darüber hinaus marktübergreifende digitale Ökosysteme...

We study empirically the price effects of upstream cartels that sell through downstream retailers to final consumers. We focus on a German coffee producer cartel that colluded under two different regimes: (i) involving wholesale prices in 2003 and (ii) with additional resale price maintenance...

Platform businesses have been pivotal in the rise of the digital economy. Amazon is one example of a platform taking on the role of a quasi-regulator; an entity that is able to determine the terms of interaction on the platform. This intermediary position entails the danger of anti-competitive...

Empirical evidence that horizontal shareholding has created anticompetitive effects in airline and banking markets have produced calls for antitrust enforcement. In response, others have critiqued the airline and banking studies and argued that antitrust law cannot tackle any anticompetitive...

This comment was filed with the Department of Justice Antitrust Division on December 31, 2009, as "Comments Regarding Agriculture and Antitrust Enforcement Issues in Our 21st Century Economy" in response to the DOJ/USDA request for public comments for the agencies' joint workshops on antitrust...

A bundled discount occurs when a seller charges less for a bundle of goods than for its components when sold separately. A characteristic of such discounting is that a rival who makes only one of the products in the bundle may have to give a larger per item discount in order to compensate the...