Accumulating evidence points to the need for more vigorous antitrust enforcement in the United States in three areas. First, stricter merger control is warranted in an economy where large, highly efficient and profitable “superstar” firms account for an increasing share of economic activity....

Recent literature has suggested that antitrust regulation is an appropriate response to labor market monopsony. This article qualifies the primacy of antitrust by arguing that a significant degree of labor market power is “frictional,” that is, without artificial barriers to entry or...