Us Antitrust Law: Central, but Unique

US antitrust law has long influenced all who deal with competition law—sometimes as a model, sometimes as a source of experience and insights, and sometimes as a surrogate for an “international standard.” It also has great practical importance in international business. This chapter provides information and insights necessary for understanding its roles and engaging with its rules and procedures. The chapter explains its institutional structures, basic principles of substantive law, and the central role of economic analysis in deciding cases. In particular, it throws light on the unique way in which judicial decisions (case law) guide decisions in all institutions and on the central significance of the categories of “rule of reason” and “per se treatment.” It also provides insights into the dynamics of the regime—the factors that drive antitrust decisions. It also sketches the ways in which it exercises influence on other competition law regimes.