Over the next couple of weeks I plan to blog about some new research, with a particular focus on unusual techniques or interesting research questions. Several of the research projects I will discuss came to my attention through the Law and Society Conference in Montreal at the end of May.
One interesting presentation was a paper entitled Hustle and Flow: A Social Network Analysis of the American Federal Judiciary by Daniel M. Katz and Derek K. Stafford, both political science graduate students at the University of Michigan. Katz and Stafford are interested in the social structure of the judiciary and, more controversially, whether that structure has an effect on doctrine or case outcomes. Different from the prevailing models of judicial behavior (attituindalism, legalism, or the strategic model), their hypothesis is that judges -- at least sometimes -- are influenced by "peer effects," not just by their own political views or by legal sources. (Such social pressures could be a partial explanation for the panel and circuit effects documented on appellate courts. See, for example, Kastellec, Jonathan P., "Panel Composition and Voting on the U.S. Courts of Appeals Over Time" (May 14, 2008). Available at SSRN: http://ssrn.com/abstract=1012111) and Kim, Pauline T., "Deliberation and Strategy on the United States Courts of Appeals: An Empirical Exploration of Panel Effects" (March 31, 2008). Available at SSRN: http://ssrn.com/abstract=1115357 ).
In order to study these social or peer effects, they must find a way to describe the social networks of the judiciary. As an initial attempt to do so, Katz and Stafford employ new network analysis techniques to measure the paths that law clerks take between judges. In other words, they chart the likelihood that a law clerk for, say, Judge Kozinski, will later clerk for Justice Kennedy, or that a law clerk for a particular district court judge will go on to clerk for a particular appellate court judge. Their study "visualizes law clerk traffic" during the last Rehnquist natural court and produces some interesting representations of the relationships between judges. (They identified about 900 clerks who moved from one judge to another during this period.)
The graphic depiction of these law clerk moves is one of the more interesting aspects of the study. In one depiction, Supreme Court justices are, not surprisingly, clustered in the middle, but -- more surprisingly -- district court judges are "suffused throughout the network," not relegated to the periphery. This is one representation, Katz and Stafford suggest, of the fact that judges with equivalent institutional authority in fact have different levels of influence. Below is one such figure from the paper -- the Kamada Kawai Energized Network. (Yellow nodes are Supreme Court justices; green are appellate court; and blue are district court judges.)