The Influence of Judicial Ideology on the Use of Precedent

Anthony Niblett 

University of Toronto - Faculty of Law

Albert Yoon 

University of Toronto - Faculty of Law
May 22, 2013

Abstract:      
Legal scholars have long argued that judges are ideologically motivated when deciding cases, constrained only by judicial review or legislative oversight. Recent empirical research, consistent with this claim, shows that federal judges appointed by Democratic presidents decide cases differently than those appointed by Republican presidents. Largely overlooked, however, is how judicial ideology influences how judges write opinions and how judges use legal precedent.

We test the hypothesis that the citation of precedents in a legal opinion is influenced by the ideological make up of the presiding panel. We create a unique dataset of every citation by the U.S. Court of Appeals in unanimous opinions from 1971-2007 to a Supreme Court decision from 1953-2007. Our results provide strong evidence that judicial ideology influences how judges cite Supreme Court precedent. Panels with more Republican-appointed judges are more likely to favorably cite conservative precedent and criticize or distinguish liberal precedent. Counterintuitively, this effect is weaker in a small subset of cases in "political" areas of law where panel composition is highly correlated with the outcome of the case.

Number of Pages in PDF File: 31

Keywords: Judges, Precedent, Courts, Judicial behavior, Citation behavior, Politics, Law & Economics

JEL Classification: K4, K40, D7

Full text available at: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2268707