Researchers have long used federal court data assembled by the Administrative Office of the U.S. Courts (AO) and the Federal Judicial Center (FJC). The data include information about every case filed in federal district court and every appeal filed in the twelve nonspecialized federal appellate courts. Much research using the AO data spans subject matter areas, and includes articles on appeals, caseloads and case-processing times, case outcomes, the relation between demographics and case outcomes, class actions, diversity jurisdiction, and litigation generally. Other research using the AO data covers particular subject matter areas, such as inmate cases, contract cases, corporate litigation, antitrust litigation, patent litigation, employme...