The institutional design of federal merger review in the United States leads to systematic underenforcement of merger law. This is so even though substantive merger law is relatively well settled, most mergers are not anticompetitive, and the review process properly permits them to proceed...

Antitrust populists increasingly call on the government to “break up big tech.” But antitrust enforcers would face heavy evidentiary burdens if they sought to break a company up on the premise that a long-consummated merger was unlawful from the outset and should have been blocked years ago....

How does employer market power affect workers? We compute the concentration of new hires by occupation and commuting zone in France using linked employer-employee data. Using instrumental variables with worker and firm fixed effects, we find that a 10% increase in labor market concentration...

Mergers lead to larger firms and a less competitive market structure, but their effects on innovation are not clear. Mergers may improve innovation incentives by promoting economies of scope and scale, R\&D activities, and increasing the ability to deal with uncertainties. However, mergers may...

The impact of innovation on mergers has been a subject of debate in merger enforcements. Firms may decide to merge because of increasing market share and expanding capacity. However, mergers may also be motivated by innovation since they provide resources for commercialization of innovation and...

How does employer market power affect workers? We compute the concentration of new hires by occupation and commuting zone in France using linked employer-employee data. Using instrumental variables with worker and firm fixed effects, we find that a 10% increase in labor market concentration...

How does employer market power affect workers? We compute the concentration of new hires by occupation and commuting zone in France using linked employer-employee data. Using instrumental variables with worker and firm fixed effects, we find that a 10% increase in labor market concentration...

The U.S. health care system is organized around markets. There has, however, been ongoing concern about the functioning of these markets, so much so that some have despaired of these markets working at all. The policy response to this concern has been disjointed. Health care markets are subject...

The U.S. health care system is organized around markets. There has, however, been ongoing concern about the functioning of these markets, so much so that some have despaired of these markets working at all. The policy response to this concern has been disjointed. Health care markets are subject...

In this chapter we review issues relating to antitrust and competition in health care markets. The chapter begins with a brief review of antitrust legislation. We then discuss whether and how health care is different from other industries in ways that might affect the optimality of competition....