Abstract

This chapter explores the actual degree of predictability of outcomes of cases, as well as the votes of individual justices. It presents three hypotheses about the predictability of outcomes, and all are verified. Accuracy of predictions emerges much more strongly for cases involving ideology-driven issues; some justices are more predictable than others; and the statistical model fared fairly well in most types of cases, but the experts' predictions were not much higher than chance. However, no system of prediction is perfect. Of 72 cases in the 2002-2003 term, in seven, the decision of the Court was contrary to the prediction from the statistical model and that of every expert used by the Washington University Forecasting Project.