The Ideologies of Organized Interests and Amicus Curiae Briefs: Large-Scale, Social Network Imputation of Ideal Points

Abstract

Interest group ideology is theoretically and empirically critical in the study of American politics, yet our measurement of this key concept is lacking both in scope and time. By leveraging network science and ideal point estimation, we provide a novel measure of ideology for amicus curiae briefs and organized interests with accompanying uncertainty estimates. Our Amicus Curiae Network scores cover more than 12,000 unique groups and more than 11,000 briefs across 95 years, providing the largest and longest measure of organized interest ideologies to date. Substantively, the scores reveal that: interests before the Court are ideologically polarized, despite variance in their coalition strategies; interests that donate to campaigns are more conservative and balanced than those that do not; and amicus curiae briefs were more common from liberal organizations until the 1980s, with ideological representation virtually balanced since then.

CHORUS: A New Dataset of State Interest Group Policy Positions in the United States

“…Second, scholars have leveraged emerging data sources on interest group policy positions to jointly define ideal points for interest groups and politicians at both the national and state levels (Crosson, Furnas, and Lorenz 2020;Thieme 2018Thieme , 2019, or done the same using campaign contributions as a proxy for preferences (Bonica 2014), and recently combined campaign contributions and a network of co-signed Supreme Court briefs to estimate interest groups' ideal points in the judicial domain (Abi-Hassan et al 2023). These ideal points provide important insights into the interplay of interest groups, political parties, and polarization.…”

Flexible Estimation of Policy Preferences for Witnesses in Committee Hearings

“…An empirical test of preference dependence in communication requires a strategy for measuring the preferences of each type of actor. Recently, several studies have developed measurement strategies that place the preferences of legislators and outside agents on a one-dimensional common space (Abi-Hassan et al 2023;Barberá 2015;Battista, Peress, and Richman 2022;Bonica 2013;Crosson, Furnas, and Lornez 2020;McKay 2008;Shor, Berry, and McCarty 2010). Legislators' preferences tend to be defined over the implications of a legislative action on their reelection prospects, and hence legislator preference measures inferred from roll calls are informed by partisanship or left-right ideology (Tausanovitch and Warshaw 2017).…”