Predicting Supreme Court Decisions Mathematically: A Quantitative Analysis of the “Right to Counsel” Cases

This study represents an attempt to apply quantitative methods to the prediction of human events that generally have been regarded as highly uncertain, namely, decisions by the Supreme Court of the United States. The study is designed to demonstrate that, in at least one area of judicial review, it is possible to take some decided cases, to identify factual elements that influenced the decisions, to derive numerical values for these elements by using a formula, and then to predict correctly the decisions of the remaining cases in the area specified. The analysis will be made independently of what the Court said by way of reasoning in these cases; it will rely only on the factual elements which have been emphasized by the justices in their opinions and on their votes to affirm or set aside convictions. Changes in Court personnel made no decisive difference in the pattern of judicial action in this area; so the analysis will not need to take into account the fact that twenty-five different justices have occupied the nine seats on the Court during the period covered, i.e. , the past quarter century.