Interest Group Success in the Courts: Amicus Participation in the Supreme Court

Abstract

Over the past two decades there has been a rapid increase in the number of amicus curiae briefs filed in the Supreme Court. Some cases studied suggest that these briefs may have a substantial effect on the Supreme Court's decisions, but no systematic studies have examined the efficacy of such briefs. The present study utilizes a precision matching strategy to determine if litigants supported by amici have a greater chance of success in the Supreme Court than comparable litigants in matched pairs who have no amicus support. The analysis uncovers no evidence that support from amici substantially increases the chance of success of the supported litigants.