with the goal of presenting the subject in a manner that refl ects modern thinking in both the law and the economics of antitrust. That is not an easy task. Antitrust economics has become a very complicated fi eld. It requires specialization, and as a result it is quite diffi cult to stay abreast of both the law and the modern economic treatments. Any eff ort to provide a balance of legal and economic analysis, given the long history of the law and the level of sophistication in modern economic research, will necessarily involve some sacrifi ce of both approaches. I am not sure it is possible to present a book that off ers the combination of everything an antitrust law specialist would like to see, as well as everything an antitrust economist would like to see. But I think it is better to sacrifi ce a bit from both of the endpoints to produce something that blends the two approaches, which is what this volume attempts to do. The argument for incorporating economic analysis in any modern discussion of antitrust law is obvious today. American courts use economic reasoning to reach conclusions on the best policies to adopt in antitrust cases. American antitrust litigation relies heavily on the input of experts trained in economics and statistics. It would be educational malpractice to train any law student to practice antitrust without communicating the importance of economic analysis to the student.