Strategic Cooperation: Modeling Concurring Behavior on the U.S. Supreme Court

Abstract

How do competing motivations influence the decisions of justices to author concurring opinions? Justices must balance their desire to shape the law and public policy toward their preferred position with the need for strong and stable coalitions. We construct a theoretical model of cooperative behavior that explicitly accounts for the competing individual- and group- level considerations of U.S. Supreme Court justices. Our theory identifies conditions specific to justices, coalitions, and cases that make the authoring of a separate opinion attractive to justices. We test these expectations using data from 40 years of justice votes within some 4,500 cases. The results of our empirical analyses support our theoretical expectations and show that the choice of a justice in the initial majority to write separately is conditional on characteristics of the justices and the coalition. We also highlight the important implications of our findings for the study of judicial decision making and policy-making more generally.

Keywords: Supreme Court, decision-making, strategy, concurrence, multilevel modeling