Friends of the Circuits: Interest Group Influence on Decision Making in the U.S. Courts of Appeals


  • *Direct correspondence to Paul M. Collins, Jr., Department of Political Science, University of North Texas, 125 Wooten Hall, 1155 Union Circle #305340, Denton, TX 76203-5017 〈〉. Paul M. Collins, Jr. will share all data and coding information with those wishing to replicate this study. This article reflects the views of the authors and does not necessarily reflect the views of the National Science Foundation. Martinek does, however, gratefully acknowledge the support of the NSF. An earlier version of this article was presented at the 2008 Annual Meeting of the American Political Science Association. The participants on that panel, especially Jolly Emrey and Pamela Corley, are owed special thanks for the insights and feedback they shared. The authors are similarly appreciative of Corey Ditslear, David Neubauer, Karen O'Connor, and Stephen L. Wasby for their observations and commentary on earlier related work, which deepened the authors' understanding of amici. They are further grateful to Susan Haire and Ashlyn Kuersten for their data-collection efforts to extend Donald R. Songer's The United States Courts of Appeals Data Base and for answering questions with alacrity. Collins thanks the University of North Texas for a research fellowship that partially funded the collection of the data used in this project. Finally, the authors offer special thanks to Lisa Solowiej and Harold J. Spaeth for their thoughts on this and related projects. All errors and omissions remain their own, of course.


Objective. Though there is an extensive literature focused on the participation and efficacy of interest group amici curiae in the U.S. Supreme Court, there is little rigorous analysis of amici curiae in the U.S. Courts of Appeals. Here, we systematically analyze the influence of amicus curiae briefs on U.S. Court of Appeals decision making to provide insights regarding both judicial decision making and the efficacy of interest groups.

Methods. We use a probit model to capture influences on appellant success in the courts of appeals from 1997–2002.

Results. We find that amicus briefs filed in support of the appellant enhance the likelihood of that litigant's probability of success, but that amicus briefs filed in support of the appellee have no effect on litigation outcomes.

Conclusion. Amici can help level the playing field between appellants and appellees by serving to counter the propensity to affirm in the U.S. Courts of Appeals.