Understanding Large Temporal Networks and Spatial Networks: Exploration, Pattern Searching, Visualization and Network Evolution

6The US Supreme Court Citation Network

Fowler and Jeon (2008) compiled a large citation network of Supreme Court decisions citing earlier decisions. The citations came from 30,288 majority opinions written between 1789 (the year of the first Court decision) and 2002.¹ This was a Herculean task. Their primary intent was tracing the evolution of stare decisis (Justices accepting a rule to follow prior legal precedents). Using this network to compute indegree, outdegree, eigenvector centrality measures, and hub and authority scores, they also characterized each decision by these measures. We use their data for a different, but complementary, purpose –locating sets of decisions in their historical, legal, and judicial contexts. Rather than examine citations to and from single decisions, we study co-cited decisions (see Section 6.2). We then couple some of these decisions to laws enacted by the federal and state governments.

This chapter is structured as follows. A brief introduction to the Supreme Court is in Section 6.1. Summaries of co-citation in citation networks and line islands (see Section 2.9 for details) are in Section 6.2 together with some preliminary results for identified line islands. An examination of cases in an island focused on Native Americans follows in Section 6.3. Cases featuring ‘threats to social order’ in another island are in Section 6.4. They are coherent examples of using line islands to understand this long temporal network spanning more than two centuries. ...