The Depreciation of Precedent on the U.S. Supreme Court

Abstract

An enduring piece of legal wisdom contends both that the value of court opinions depreciates as they age and that a variety of factors lead some cases to depreciate faster than others. We systematically test these expectations by examining the rate at which U.S. Supreme Court precedents depreciate between the 1946 and 2004 Terms. Our statistical results indicate, first, that a precedent’s age has the most pronounced influence of any variable on depreciation, and, second, that almost none of the other factors appreciably affect depreciation. There is only one exception to this latter conclusion, and the “history” of a case, as observed through the patterns in previous case citations, influences depreciation. But, even the strength of that relationship substantially depends on the age of a case. Third, we show studies overestimate the effect of nearly every variable previously used to explain case citations because those variables become less influential as cases age