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

We present a formal game theoretic model of adjudication by a collegial court. The model incorporates dispute resolution as well as judicial policy 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 policy of the median judge. The model suggests new departures for empirical work on judicial politics. This paper substantially revises a prior version dated July 1 2009