Using Citations to Measure Influence on the Supreme Court

Abstract

I develop a new measure of interpersonal influence on the U.S. Supreme Court. Following Altfeld and Spaeth, I define influence as “the act of producing an effect on the behavior of another without the use of coercion, authority, or political control.” I propose a measure of influence based on the number of times a justice cites her colleagues’ concurring and dissenting opinions. My analysis proceeds in two stages. First, I verify that this citation-based measure is a valid method of gauging influence. From there, I use this measure to help explain justice behavior in two pivotal stages of the Supreme Court’s decision-making process: oral arguments and opinion assignments. The results demonstrate that a citation-based measure of influence can help explain and predict behavior on the Supreme Court.