Earlier this week, we began a four-part post at the Illinois Supreme Court Review briefly reviewing some of the leading academic literature on the phenomenon of “panel effects” – the theory that appellate panels are a collective decision-maker rather than a group of individual decision-makers, and thus a particular judge’s vote is influenced to some degree by the characteristics of the other judges he or she is sitting with.

Today, we’re looking at two more studies which are typical of the literature, beginning with Ideological Voting on Federal Courts of Appeals: A Preliminary Investigation, John M. Olin Law & Economics Working Paper No. 198 (2003), by Professors Cass R. Sunstein, David Schkade and Lisa Michelle Ellman.  The authors assembled a massive database from the Courts of Appeals consisting of 4,488 published decisions and 13,464 separate judge votes.  Although how to define what is a “liberal” or “conservative” vote is a topic which has divided empirical researchers for generations, the authors calculated that judges appointed by a Democratic President cast 60% liberal votes, which Republican appointees cast only 46% liberal votes.

They then considered panel effects.  A panel consisting of three Democratic appointees averaged 66% liberal votes (six points higher than any randomly selected Democratic appointee alone).  When one Democrat was removed from the panel and replaced by a Republican appointee to sit with the two Democrats, the Republican cast 54% liberal votes (eight points higher than a given Republican alone).  Pair a single Democrat with two Republicans, and the Democratic appointee dropped seven points to 53% liberal votes.

The authors then isolated campaign finance decisions in the database, measuring how often each panel voted to uphold a regulation.  Here, ideological diversity had a substantial impact.  A panel consisting of one Republican appointee and two Democrats upheld only 35% of regulations.  Two Republicans and one Democrat dropped that percentage an additional five points.  A panel of three Republicans upheld only 23% of regulations.  Swap one Republican out for a Democratic appointee, and that rose to 40%.  Two Democrats and a Republican had almost the same result – 38%.  Only before panels consisting of three Democratic appointees was there a substantial impact, as 73% of regulations were upheld.

In 2012, Professor Robert Steinbuch published An Empirical Analysis of Conservative, Liberal and other ‘Biases’ in the United States Courts of Appeals for the Eighth and Ninth Circuits, 11 Seattle Journal for Social Justice 217 (2012).  Professor Steinbuch collected large databases of cases from the Eighth and Ninth Circuits, collecting several variables from each case: the political party and gender of the trial judge, the number of appeals taken in the past year from the judge’s decisions and the types of cases appealed.  For the 2008 Eighth Circuit data, the author concluded that there was a statistically significant correlation between the political affiliation of the district judge appealed from and the rate of reversal.  For the 2011 cases from the Eighth Circuit, the author concluded that the Court reversed Democratic appointees 15% often than Republican appointees.  On the other hand, for the 2,610 cases in the database from the Ninth Circuit, the article concludes that there was no correlation between the result on appeal and the party of the district judge.

Join us back here next time as we continue our trip through the literature on panel effects.

Image courtesy of Flickr by Damian Gadal (no changes).