Measuring Precedent in a Judicial Hierarchy

The Supreme Court of the United States primarily impacts society through doctrine created or sustained in their opinions (Hall 2010). Any understanding of the Court's role in American society must therefore include an understanding of which precedents exert the most legal influence, and why. Scholars overwhelmingly make these determinations based on how often subsequent Supreme Court opinions cite a given precedent. When scholars analyze precedents in this manner for "legal significance," (Fowler and Jeon 2008) does this term mean that a precedent is well-known? Or does it mean that other judges defer to the precedent's holding regularly? While noteworthiness and jurisprudential influence could be correlated, they are distinct in theory.It cannot be assumed that measuring the general relevance of a given precedent also captures its doctrinal significance. Approaches relying on citations in Supreme Court opinions can measure general relevance quite well, however, they are less suitable for capturing legal authority. In support of this contention, I present an analysis of original data on the treatment of every Court precedent 1946-2010 in all three levels of the federal judicial hierarchy.Analysts must make two methodological choices when measuring legal precedent. First, in any hierarchical legal system, analysts must decide at which level or levels of that system they wish to measure the significance of individual precedents. In the United States, judges at the district, circuit, and Supreme Court levels all face different operative incentives and constraints (Baum 1994). Due to these constraints, perhaps district judges are more likely than others to allow legalistic concerns to predominate when crafting opinions. Similarly, in other contexts, it could be expected that the lower rungs of any judicial hierarchy would be least able to innovate ideologically, due to resource and opportunity constraints (Choi, Gulati, and Posner 2012; Epstein and Knight 2013; Pinello 1999; Wold and Caldeira 1980).The second choice analysts face is whether to consider the language of the citing opinions directly. Some citations to precedent are incidental, others are negative, and some are deferential. Fowler et al. (2007); Fowler and Jeon (2008), and Patty, Penn, and Schnakenberg (2013) focus on a citation's networked position and analyze all types of citations, positive, negative, and neutral, together. Alternatively, Hansford and Spriggs (2006) consider the nature of citations when measuring precedent, at the Supreme Court level exclusively. Considering only deferential treatments may better capture jurisprudential treatments than would considering all citation types together. Ultimately, a reasonable method for measuring the broader jurisprudential significance of Supreme Court precedent involves aggregating how often a precedent is followed (according to Shepard's Citations) across all three levels of the federal judicial hierarchy.1 Conversely, when analysts set out to measure which precedents are relevant to a court in a more broad sense (Clark and Lauderdale 2012; Fowler et al. 2007; Fowler and Jeon 2008), considering all citation types appears to be the better option.I illustrate the tradeoffs of these two choices by exploring how varying methods of measuring precedent track fractious, logically inconsistent decisions. I discuss the definition of these paradoxical decisions, known as discursive dilemmas or doctrinal paradoxes (Kornhauser and Sager 1986; Pettit 2001; Stearns 2000), in detail below. Precedents stemming from a paradox are by definition ambiguous, and are, therefore, quite challenging to follow in a jurisprudential manner.In brief, paradoxes are decisions for which every possible rationale for the Court's judgment is rejected by a majority of the justices, yet the judgment itself still gets a majority vote through the aggregation of votes by desired outcome. Lower courts struggle to follow paradoxes because it is unclear which line of reasoning ought to apply (Post and Salop 1992). …