Bargaining Power in the Supreme Court: Evidence from Opinion Assignment and Vote Switching

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected].. The University of Chicago Press and Southern Political Science Association are collaborating with JSTOR to digitize, preserve and extend access to The Journal of Politics. How can we assess relative bargaining power within the Supreme Court? Justices cast two votes in every case, one during the initial conference and one on the final merits of the case. Between these two votes, a justice is assigned to draft the majority opinion. We argue that vote switching can be used to detect the power of opinion authors over opinion content. Bargaining models make different predictions for opinion content and therefore for when other justices in the initial majority should be more or less likely to defect from initial positions. We derive hypotheses for how opinion authorship should affect vote switching and find that authorship has striking effects on switching. Authors thus have disproportionate influence and by extension so do chief justices, who make most assignments. This evidence is compatible with only the " author influence " class of bargaining models, with particular support for one model within this class. A t the end of each Supreme Court term, there is much talk in the popular media of whose " Court " it is—that is, which justice was particularly influential or who was the pivotal swing justice. After an unusually extended period of stability, the ideological makeup of the Court has shifted in recent years, beginning with the 2006 retirement of Justice O'Connor, who was known for being a swing justice. When Justice Alito took her place, the label of pivotal swing vote shifted firmly to Justice Kennedy, and perhaps rightly so. In the 2006–7 term, Kennedy was in the majority in all 24 of the Court's 5-to-4 decisions, and the media proclaimed the beginning of the " Kennedy Court. " Despite a precipitous drop in 5-to-4 decisions in the 2007– 8 term (from 24 to 11), the New York Times maintained, " It was, once again, Justice Kennedy's Court " (Greenhouse 2008). Meanwhile, Roberts replaced Rehnquist as chief justice , a change in the most procedurally powerful Court position. Now that Roberts has …