Panel Composition and Voting on the U.S. Courts of Appeals Over Time

40 Pages Posted: 11 Sep 2007 Last revised: 15 May 2008

See all articles by Jonathan P. Kastellec

Jonathan P. Kastellec

Princeton University - Department of Political Science

Date Written: May 14, 2008


Studies of the the U.S. Courts of Appeals increasingly have moved beyond studying the voting behavior of judges in isolation from their panel colleagues and toward an approach that takes into account how panel composition can affect both individual judicial decisions and, as a result, the final decisions of three-judge panels. This paper makes two contributions to this burgeoning literature on panel composition and panel effects in the Courts of Appeals. I present the first assessment of the rates of various panel configurations over time on the Courts of Appeals, based on the partisanship of judges. I show that while long stretches of single-party control of the presidency in the first half of the 20th century often led to low degrees of panel heterogeneity, more frequent turnover of White House control in the last half-century has helped ensure that a majority of panels are composed of at least one judge from each party. Second, this paper presents the first longitudinal analysis of the relationship between panel composition and judicial behavior. Examining aggregate patterns in Courts of Appeals decisions from 1961 to 2002, I show that the difference in voting between unified Republican and unified Democratic panels is a relatively recent phenomenon, and only appeared beginning in the 1980s. Similarly, the existence of panel effects is also a recent development, exists mostly among Democratic appointees to the bench, and not Republican appointees. These results have important positive and normative implications for the study of the Courts of Appeals and for proposals to reform panel selection procedures.

Keywords: courts of appeals, panel composition, panel effects, voting, judging

Suggested Citation

Kastellec, Jonathan P., Panel Composition and Voting on the U.S. Courts of Appeals Over Time (May 14, 2008). 3rd Annual Conference on Empirical Legal Studies Papers, Available at SSRN: or

Jonathan P. Kastellec (Contact Author)

Princeton University - Department of Political Science ( email )

Fisher Hall
Department of Politics
Princeton, NJ 08544-1012
United States

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics