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...

We examine the capital-market effects of changes in securities regulation in the European Union (EU) aimed at reducing market abuse and increasing transparency. To estimate causal effects for the population of EU firms, we exploit that for plausibly exogenous reasons, like national legislative...

This paper considers the recent literature on firm markups in light of both new and classic work in the field of Industrial Organization. We detail the shortcomings of papers that rely on discredited approaches from the “structure-conduct-performance” literature. In contrast, papers based on...

While economic theories indicate that market power by downstream firms can potentially counteract market power upstream, antitrust policy is opaque about whether to incorporate countervailing market power in merger analyses. We use detailed national claims data from the healthcare sector to...

Many standard setting organizations (SSOs) require participants to disclose patents that might be infringed by implementing a proposed standard, and commit to license their “essential” patents on terms that are at least fair, reasonable and non-discriminatory (FRAND). Data from these SSO...

We propose a method for bounding the demand elasticity in growing, homogeneous-product markets that requires only minimal data—market price and quantity over a time span as short as two periods. Reminiscent of revealed-preference arguments using choices over time to bound the shape of...