Building a Taxonomy of Litigation: Clusters of Causes of Action in Federal Complaints

This project empirically explores civil litigation from its inception by examining the content of civil complaints. We utilize spectral cluster analysis on a newly compiled federal district court data set of causes of action in complaints to illustrate the relationship of legal claims to one another, the broader composition of lawsuits in trial courts, and the breadth of pleading in individual complaints. Our results shed light not only on the networks of legal theories in civil litigation but also on how lawsuits are classified and the strategies that plaintiffs and their attorneys employ when commencing litigation. This approach permits us to lay the foundation for a more precise and useful taxonomy of federal litigation than has been previously available, one that, after the Supreme Court's recent decisions in Bell Atlantic v. Twombly (2007) and Ashcroft v. Iqbal (2009), has also arguably never been more relevant than it is today.