Catholic University Law Review


Intellectual property law in the United States, though shaped by key statutes, has long been a common-law field to a great degree. Many decades of decisional law flesh out the meaning of broad-textured, sparely worded statutes. Given the key roles of patent law and copyright law, both federal, the Supreme Court of the United States is i.p. law’s leading apex court. What are the major topical currents in the Supreme Court’s i.p. cases, both now and over the course of the Court’s work? This study uses network-analysis tools to measure and map the entirety of the Court’s i.p. jurisprudence. It goes deeper than existing studies of judicial citation networks by focusing on a topically defined subnetwork. It goes further than existing studies by analyzing, in addition to basic citation networks, a time series of co-citation networks—using techniques developed within bibliometrics, for mapping a scholarly field’s conceptual terrain, to track and describe doctrinal change. Emerging bottom up from the Court’s citations, the co-citation map charted here reveals, surprisingly, a core of antitrust and patent misuse cases from the 1920s–1940s exerting significant influence on i.p. doctrine. It also helps highlight how the substance of the Court’s recent i.p. decisions, from 1986 to 2019, differ from what came before.