Market definition and market power are central features of competition law and practice but pose serious challenges. On one hand, market definition suffers decisive logical infirmities that render it infeasible, unnecessary, and counterproductive, and the practice of stating market power...

Market power is the most important determinant of liability in competition law cases throughout the world. Yet fundamental questions on the relevance of market power are underanalyzed, if examined at all: When and why should we inquire into market power? How much should we require? Should market...

The prohibition of certain types of anticompetitive unilateral conduct by firms possessing a substantial degree of market power is a cornerstone of competition law regimes worldwide. Yet notwithstanding the social costs of monopoly modern legal regimes refrain from prohibiting it outright....

The ministerial proposal for a 10th amendment of the German competition law particularly addresses abuse control and seeks to tighten this pillar of competition policy against the background of the challenges from the digital economy. Next to extending the classic policy instruments of abuse...

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...

This comment addresses the opinion of the Advocate General (AG) of the European Court of Justice on the pending case European Super League versus UEFA/FIFA. It takes a critical perspective on selected aspects of the opinion’s reasoning from a (sports) economics perspective. Highlighting the...

Economists have long recognized the National Collegiate Athletic Association (NCAA) as a monopsonistic cartel that restrains athlete labor compensation below competitive market levels. However, an additional restraint has been heretofore ignored. This article argues that NCAA justifies the...

Does significant market power or the presence of large rents affect optimal income taxation, calling for greater redistribution due to tainted gains? Or perhaps less because of an additional wedge that distorts labor effort? Do concerns about inequality have implications for antitrust,...

Antitrust is back in vogue at the U.S. Supreme Court. Whereas the Rehnquist Court decided few antitrust cases in its latter years (only one from 1993 to 1995, one each year from 1996 through 1999, and none from 2000 to 2003), the Roberts Court issued seven antitrust decisions in its first two...