Network Analysis of Transjurisdictional Citations in Judicial Opinions: Sources of Persuasive Authority in the Inter-Court Dialogue

The emergence of a transjurisdictional dialogue between constitutional courts is one of the major factors affecting judicial decisionmaking in constitutional cases in the last several decades, as judges increasingly turn towards their peers from other jurisdictions for persuasive authority. Yet this process has been mostly analyzed through the lens of anecdotal evidence, with researchers concentrating on case studies focused on particularly prominent decisions, especially in the politically charged field of human rights. We instead propose to employ big data analysis methods in the form of a network analysis of the judicial citation graph to test a number of hypotheses regarding the factors affecting courts’ attractiveness as a source of persuasive authority. Our unique dataset consists of citations in separation of powers cases from U.S. state supreme courts. This gives us a large number of network nodes (50 state supreme courts), ensures that all decisions share the same legal system and similar institutional backgrounds (avoiding an important source of statistical irregularities) and, by picking less politically charged area, allows us to explore institutional as well as political factors affecting persuasive authority of the state supreme courts.