Measuring Ideological Polarization on the United States Supreme Court

The study of ideological polarization is an important topic in research ranging from behavioral-level to institutional studies of politics. Polarization, however, has received little attention in the context of the Supreme Court, even while popular press and legal commentary suggest ideological heterogeneity on the Court is consequential for the Court's policy outputs. In this article, I apply an axiomatic measure of polarization developed by Esteban and Ray (1994) to study ideological heterogeneity on the Court to develop a "polarization statistic." I compare this method with other common polarization measures and provide evidence for the reliability of the measure.