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...

The diversion ratio for products j and k can be interpreted as the result of an experiment: increase the price of product j, measure the number of consumers who leave product j, and then measure the fraction of leavers who switch to a substitute product k. In theory, this is expressed as the...

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...

Although antitrust courts sometimes stress the competitive process, they have not deeply explored what that process is. Inspired by the theory of the core, we explore the idea that the competitive process is the process of sellers and buyers forming improving coalitions. Much of antitrust can be...

Governments rescue private companies partly to prevent other firms from gaining excessive market power. However, if failing firms exit, new entry may limit remaining firms' market power if there are potential entrants who can be as effective competitors as the firms leaving the market. We...

We develop a framework that may be used to determine the degree to which a school choice program may harm public school stayers by luring the best students to other schools. This framework results in a simple formula showing that the "cream-skimming" effect is increasing in the degree of...