I review previous approaches to modelling oligopoly in general equilibrium, and propose a new view which in principle overcomes their deficiencies: modelling firms as large in their own market but small in the economy as a whole. Implementing this approach requires a tractable specification of...

Recent court rulings, e.g., in the Gencor and Airtours cases, seem to indicate that the legal concept of joint dominance in oligopolistic markets is equivalent to the economic concept of collusion. This paper argues that the enlargement of the dominance concept to also include oligopolistic...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

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 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...

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...

There is a growing concern that U.S. merger control may have been too lenient, but empirical evidence remains limited. Event studies have been used as one method to acquire empirical insights into the competitive effects of mergers. However, existing work suffers from strong identifying...

The markets for audiovisual content are subject to dynamic change. Where once "traditional" (free-to-air, cable, satellite) television was dominating, i.e. linear audiovisual media services, markets display nowadays strong growth of different types of video-on-demand (VoD), i.e. nonlinear...

Private equity firms (PE firms) have become common owners of established firms in concentrated markets. We show that the threat of a PE acquisition can trigger incumbent mergers in an otherwise mergerstable industry. This can help antitrust authorities maximize consumer surplus because...

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...