Why Supreme Court Justices Use Legislative History: An Empirical Investigation

Abstract

Much of the political science literature on judicial behavior has focused on the impact of ideology on how judges vote. Legal scholars, however, have been slow to embrace empirical scholarship that fails to emphasize the impact of legal constraints and the means by which judges reason their way to particular outcomes. This paper attempts to integrate and address the concerns of both audiences by way of an empirical examination of the Supreme Court's use of a particular interpretive technique - namely, the use of legislative history to determine the purpose and meaning of a statute. We examine all Supreme Court opinions decided from the 1953 through 2006 terms involving frequently interpreted federal statutes. These statutes varied in their formal legal characteristics, such as age, length, obscurity, and the extent to which they had been amended. We use logit regression analysis to evaluate the impact of these formal characteristics, as well as ideological characteristics of judges and their opinions, on the likelihood that a justice will resort in a given opinion to the use of legislative history. Our results suggest that a combination of legal and ideological factors best explains how and why justices on the modern Supreme Court have employed this interpretive technique.