The Emerging Authority of Magistrate Judges within US District Courts

The federal judicial system is a hierarchy with district courts at the bottom, courts of appeals in the middle, and the Supreme Court at the top. A second, less visible, judicial hierarchy exists within district courts, with magistrate judges situated below district judges. Existing scholarship largely ignores magistrate judges, assuming they are agents tasked with procedural matters with little independent effect on federal courts adjudication. Using a combination of national administrative data (2000–2016) and original case-level data from nine district courts (1997–2014), we find that district courts not only grant meaningful responsibility and discretion to magistrate judges but do so in ways that vary substantially across and within districts. The effects of this judicial delegation extend from procedural rulings to substantive outcomes. Our findings provide evidence that a complete understanding of federal judicial decision making accounts for the roles—procedural and substantive—that magistrate judges perform.