Modeling Collegial Courts (3): Adjudication Equilibria (Revised)

Abstract

We present a formal game theoretic model of adjudication by a collegial court. The model incorporates dispute resolution as well as making and indicates the relationship between the two. It explicitly addresses joins, concurrences and dissents, and assumes judicial rather than legislative or electoral objectives by the actors. The model makes clear and often novel predictions about the plurality opinion's location in policy space; the case's disposition; and the size and composition of the disposition-, join-, and concurrence-coalitions. These elements of adjudication equilibrium vary with the identity of the opinion writer and with the location of the case. In general, the opinion is not located at the ideal of the median judge. The model suggests new departures for empirical work on politics. This paper substantially revises a prior version dated July 1 2009.