Case Selection and the Study of Judicial Politics


  • Earlier versions of this article were presented at the Annual Meeting of the American Political Science Association, August 31–September 3, 2006, and the Annual Meeting of the Conference on Empirical Legal Studies, November 9–10, 2007. We would like to thank Michael Bailey, Cheryl Boudreau, Theodore Eisenberg, Andrew Gelman, Shigeo Hirano, David Klein, Dan Klerman, Eduardo Leoni, Justin Phillips, Kirk Randazzo, and Rebecca Weitz-Shapiro for helpful comments and suggestions, and Jeffrey Segal, Donald Songer, Charles Cameron, David Klein, and Robert Hume for generously sharing their data with us. Replication data sets and statistical code are available at 〈〉.

*Jonathan P. Kastellec, Department of Political Science, Columbia University, 420 W. 118th St., New York, NY 10027; email: Kastellec is Ph.D. candidate; Lax is Assistant Professor, Department of Political Science, Columbia University.


One complication in studying the Supreme Court and the judicial hierarchy is that the Court's docket is now nearly completely discretionary. Although the Justices’ strategies in picking cases affect the observations we make and the inferences we draw, this is rarely taken into account in studies of judicial politics. In this article, we study how case selection can affect our inferences within judicial politics, including those about decision making in the Supreme Court itself (such as whether law constrains the Justices) and throughout the judicial hierarchy (such as whether lower courts comply with Supreme Court doctrine). We use simulation analysis to show that the inferential problems raised by the Court's case selection range from moderate to severe. At stake are substantive conclusions within some of the most important and controversial debates in judicial politics.