Examining the Effects of Information, Attorney Capability, and Amicus Participation on U.S. Supreme Court Decision Making

Focusing on litigators or amicus curiae, a significant amount of scholarship has examined the impact of information on Supreme Court decision making. Taking into account that justices have varying degrees of substantive expertise across issues, we model the interaction of justice expertise with these external sources of information. Specifically, we test whether justices are more likely to be influenced by attorney capability in cases where they have less substantive legal expertise. We also explore whether justices’ reliance on amici is conditional on their own expertise, as well as the overall quality of the litigants’ attorneys. As anticipated, this research finds that as the justice’s legal expertise increases, the influence of attorney capability tends to decrease. Moreover, as the expertise of the judge and/or the quality of the attorneys increase, the impact of amici tends to decrease.