At the heart of this study is an analysis of several hundred cases decided in the U. S. Courts of Appeals in the 1980s and 1990s. This chapter introduces these cases and the legal rules involved in them. First, I explain how the cases were chosen and discuss possible biases arising from the sample selection method. Next comes some information about the legal rules, meant to give the reader a more concrete sense of the types of issues contested in the cases. I then describe the Supreme Court's reactions to the new rules, showing that circuit judges had a substantial independent impact on legal policy. The chapter ends with the focus back on the circuit judges' decisions, presenting an overview of their responses to one another's precedents. Here the key questions are how often early opinions are cited and how often their rules are adopted in later cases.
The cases were drawn from three areas of law: antitrust, search and seizure, and environmental law. These fields meet four major criteria. First, they are broadly representative of the work of the federal courts, encompassing statutory and regulatory as well as constitutional law. Second, they have widespread impact; decisions in these fields matter, often to a large number of people. The third and fourth common characteristics are that the fields are neither so immature that the courts of appeals are unfettered by Supreme Court precedent nor so settled that they lack discretion in decision making.