We hand-collect and standardize information describing all 3,055 antitrust lawsuits brought by the Department of Justice (DOJ) between 1971 and 2018. Using restricted establishment-level microdata from the U.S. Census, we compare the economic outcomes of a non-tradable industry in states...

Competition in many important industries centers on investment in intellectual property. Firms engage in dynamic, Schumpeterian competition for the market, through sequential winner-take-all races to produce drastic innovations, rather than through static price/output competition in the market....

Antitrust enforcement in the United States has declined since the 1960s. Building on several new datasets, we argue that this decline did not reflect a popular demand for weaker enforcement or any other kind of democratic sanction. The decline was engineered by unelected regulators and judges...

We study common ownership in 49 countries from 2005 to 2019 and show that it is pervasive and rising around the world. However, despite this global growth, common ownership is still considerably lower in all countries compared to the United States. It is particularly high and growing rapidly...

Has the United States economy become less competitive in recent decades? One might think so based on a body of research that has rapidly become influential for antitrust policy. We explain that the empirical evidence relating to concentration trends, markup trends, and the effects of mergers...

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 definition is essential to merger analysis. Because no standard approach to market definition exists, opposing parties in antitrust cases often disagree about the extent of the market. These differences have been particularly relevant in the hospital industry, where the courts have denied...

We document the effects of a comprehensive set of US retail mergers. On average, prices increase by 1.5% and quantities decrease by 2.3%, with significant heterogeneity in outcomes across mergers. Price changes correlate with the screens codified in the Horizontal Merger Guidelines. Through a...

This article explores subjects in optimal income taxation characterized by recent research interest, practical importance in light of concerns about inequality, potential for misunderstanding, and prospects for advancement. Throughout, the analysis highlights paths for further investigation....