The Chicago School has produced many significant contributions to the antitrust literature of the last half century. Thanks in part to Chicago School efforts today we have an antitrust policy that is more rigorously economic, less concerned with protecting noneconomic values that are impossible to identify and weigh, and more confident that markets will correct themselves without government intervention. This Chicago School revolution came at the expense of the Harvard structural school, which flourished from the 1930s through the 1950s. That school rested on a fairly rigid theory of Cournot oligopoly, exaggerated notions about barriers and impediments to entry, and a belief that certain types of anticompetitive conduct were more-or-less inevitable given a particular market structure. However, the chastised Harvard School that emerged in the late 1970s in the writings of Phillip E. Areeda and a converted Donald F. Turner were much less ambitious about the goals of antitrust, more concerned with conduct as such, and significantly more skeptical about the benefits of aggressive judicial intervention.
This story of a victorious Chicago School and a humbled and disciplined Harvard School is incomplete, however. The antitrust case law reveals something quite different. On most of the important issues this chastised Harvard School has captured antitrust decision making in the courts, and largely in the enforcement agencies. This paper explores these differences, focusing mainly on dominant firm practices.
Hovenkamp, Herbert J., "The Harvard and Chicago Schools and the Dominant Firm" (2007). Faculty Scholarship. 1771.