Modeling Supreme Court Strategic Decision Making: Congressional Constraint

This paper addresses the contradictory results obtained in Segal (1997) and Spiller and Gely (1992) concerning the impact of institutional constraints on the US Supreme Court decisionmaking. by adapting the Spiller and Gely model to the data set utilized by Segal. The major findings are as follows: first, by adapting the Spiller and Gely (1992) maximum likelihood model to the Segal (1997) dataset, we find support for the hypothesis that the Court adjusts its decisions to Presidential and congressional preferences. Second, data from 1947-92 indicate that the average probability of the Court being constrained has been approximately one third. Third, we show that the results obtained in Segal (1997) are the product of biases introduced by a misspecified econometric model. Finally, the estimation highlights the usefulness of Krehbiel’s model of legislative decision-making.