Research

The Ideologies of Organized Interests & Amicus Curiae Briefs: Large-Scale, Social Network Imputation of Ideal Points. Political Analysis (Sahar Abi-Hassan, Janet Box-Steffensmeier, Dino P. Christenson, Aaron Kaufman and Brian Libgober). Appendix | Bibtex | AbstractInterest 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 (ACNet) 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.

Keywords: Interest groups, Ideology, Ideal points, Social networks, Amicus curiae

Cue-Taking in Congress: Interest Group Signals from Dear Colleague Letters. American Journal of Political Science 63(1): 163-180 ( Janet M. Box-Steffensmeier, Dino P. Christenson and Alison W. Craig). Data | Bibtex | Abstract Why do some pieces of legislation move forward while others languish? We bring new insights to this fundamental question by examining the role of interest groups in Congress, specifically the impact of legislative endorsements from Dear Colleague letters, which provide insight into the information that members use to both influence and make policy decisions. We demonstrate that endorsements from particularly well connected interest groups are a strong cue early in the legislative process, helping to grow the list of bill cosponsors. As bills progress, such groups have less direct weight, while legislation supported by a larger number of organizations and a larger number of cosponsors is more likely to pass. Thus, we illuminate the usage of Dear Colleague letters in Congress, demonstrate how members use interest groups in the legislative process, and shed new light on the impact that the preferences of elite interests have on public policy.

Keywords: Dear Colleague letters, Interest groups, Congress, Cosponsorship, Social networks

Substantive Implications of Unobserved Heterogeneity: Testing the Frailty Approach to Exponential Random Graph Models. Social Networks, 59: 141-153 ( Janet M. Box-Steffensmeier, Benjamin Campbell Dino P. Christenson and Jason W. Morgan). Appendix | Data | Bibtex | Abstract Exponential Random Graph Models (ERGMs) are an increasingly common tool for inferential network analysis. However, a potential problem for these models is the as- sumption of correct model specification. Through six substantive applications (Mesa High, Florentine Marriage, Military Alliances, Militarized Interstate Disputes, Re- gional Planning, Brain Complexity), we illustrate how unobserved heterogeneity and confounding leads to degenerate model specifications, inferential errors, and poor model fit. In addition, we present evidence that a better approach exists in the form of the Frailty Exponential Random Graph Model (FERGM), which extends the ERGM to account for unit or group-level heterogeneity in tie formation. In each case, the ERGM is prone to producing inferential errors and forecasting ties with lower accuracy than the FERGM.

Keywords: Inferential network analysis; ERGM; Unobserved heterogeneity; Frailty term; Model fit; Simulated networks; Florentine marriage; Military alliances; Regional planning; Militarized disputes; Brain networks

Modeling Unobserved Heterogeneity in Social Networks with the Frailty Exponential Random Graph Model. Political Analysis, 26(1): 3-19 ( Janet M. Box-Steffensmeier Dino P. Christenson and Jason W. Morgan). Data | Bibtex | Abstract In the study of social processes, the presence of unobserved heterogeneity is a regular concern. It should be particularly worrisome for the statistical analysis of networks, given the complex dependencies that shape network formation combined with the restrictive assumptions of related models. In this paper, we demonstrate the importance of explicitly accounting for unobserved heterogeneity in exponential random graph models (ERGM) with a Monte Carlo analysis and two applications that have played an important role in the networks literature. Overall, these analyses show that failing to account for unobserved heterogeneity can have a significant impact on inferences about network formation. The proposed frailty extension to the ERGM (FERGM) generally outperforms the ERGM in these cases, and does so by relatively large margins. Moreover, our novel multilevel estimation strategy has the advantage of avoiding the problem of degeneration that plagues the standard MCMC-MLE approach.

Keywords: Exponential Random Graph Model (ERGM), Frailty terms, Frailty Exponential Random Graph Model (FERGM), Multiple membership mixed effects model, Monte Carlo experiments, Unobserved heterogeneity
🏆  Winner of the 2018 Political Analysis Editors' Choice Award.

Role Analysis Using the Ego-ERGM: A Look at Environmental Interest Group Coalitions. Social Networks, 52:213-227 ( Janet M. Box-Steffensmeier, Benjamin Campbell Dino P. Christenson and Zachary Navabi). Bibtex | Abstract Interest groups coordinate to achieve political goals. However, these groups are heterogeneous, and the division of labor within these coalitions varies. We explore the presence of distinct roles in coalitions of environmental interest groups, and analyse which factors predict if an organization takes on a particular role. To model these latent dynamics, we introduce the ego-ERGM. We find that a group’s budget, member size, staff size, and degree centrality are influential in distinguishing between three role assignments. These results provide insight into the roles adopted in carrying out coalition tasks. This approach shows promise for understanding a host of networks. Keywords: Network Analysis, Role Analysis, Lobbying, Environmental Politics, Ego-ERGM, Community Detection, Interest Group Coalitions, Amicus Curiae Briefs.

Keywords: Network analysis, Role analysis, Lobbying, Environmental politics, Ego-ERGM, Community detection, Interest group coalitions, Amicus curiae briefs

Why Amicus Curiae Cosigners Come and Go: A Dynamic Model of Interest Group Networks. Proceedings of the International Workshop on Complex Networks and their Applications V. Studies in Computational Intelligence, 693: 349-360 ( Janet M. Box-Steffensmeier and Dino P. Christenson). Appendix | Bibtex | AbstractInterest groups use coalition strategies to exert influence, yet, like other political actors, they also withdraw from partnerships in the pursuit of other policy goals. We explore how interest group coalition strategies have changed over time and which factors determine whether interest groups relationships form and dissolve. Utilizing dynamic networks of a panel of interest groups derived from cosigner status to United States Supreme Court amicus curiae briefs, we illuminate the evolution of the social networks of frequent signers from the 1970s to the present day. A separable temporal exponential random graph model (STERGM) shows that the number of partners is important for formation but not dissolution, while industrial homophily helps both to make and maintain connections. In addition, statistical trends suggest that while networks change, a few players have acted continuously as coordination hubs for the bulk of the decades. However, a number of other key players in particular decades would be missed without a dynamic perspective.

Keywords: Dynamic networks, Separable temporal exponential random graph model (STERGM), Interest groups, Amicus curiae network

Judicial Networks. In Oxford Handbook of Political Networks, ed. Jennifer N. Victor, Mark Lubell and Alex Montgomery, New York: Oxford University Press ( Janet M. Box-Steffensmeier, Dino P. Christenson and Claire Leavitt). Bibtex| AbstractIn this chapter we present a comprehensive summary of the literatures benefiting from the study of judicial networks. We pay particular attention to networks where exciting scholarly advances are concentrated and those that show great promise in contributing to the literature on judicial behavior and extant decision-making models. Throughout our discussions, we identify the necessary tools and measures to study these networks and describe the varying processes of data collection while highlighting the strengths and weaknesses of both the classic and most recent literatures. We classify judicial networks into three broad types. First, we explore the literature on citations networks, or networks of judicial opinions linked by references to one another. Citation networks provide crucial insights into the foundations of judicial decision-making by exposing the opinions judges believe to be most significant. Second, we look at the networks created by considering the interactions between judges, law clerks, lawyers and other relevant figures, which we call prestige networks. Such networks have the potential to reveal possible peer effects among judges and the role of social and professional relationships in determining judicial outcomes. Finally, the developing literature on amicus curiae networks, which map connections between signatories of “friend of the court” legal briefs, help identify which extralegal actors enjoy the greatest influence on the courts. More importantly, perhaps, these networks expose the often secretive relationships among organized interests that are potentially relevant across branches of government and in a host of democracies.

Keywords: Courts, Judicial branch, Social networks, Citation networks, Prestige networks, Amicus curiae networks

2015. Comparing Membership Interest Group Networks Across Space and Time, Size, Issue and Industry. Network Science, 3(1): 78-97 ( Janet M. Box-Steffensmeier and Dino P. Christenson). Appendix | Bibtex | AbstractWe compare and contrast the network formation of interest groups across industry and issue area. We focus on membership interest groups, which by virtue of representing the interests of voluntary members, face particular organizational and maintenance constraints. To reveal their cooperative behavior we build a network data set based on cosigner status to United States Supreme Court amicus curiae briefs and analyze it with exponential random graph models (ERGMs) and multidimensional scaling. We find that while many of the same factors shape membership networks, religious, labor and political organizations do not share the same struc- ture as each other or as the business, civic and professional groups. Our methodological approach culminates in a clear and compact spatial representation of network similarities and differences.

Keywords: Interest groups, membership organizations, coalition strategies, amicus curiae briefs, exponential random graph models, multidimensional scaling

The Evolution and Formation of Amicus Curiae Networks. Social Networks, 36: 82-96( Janet M. Box-Steffensmeier and Dino P. Christenson ). Appendix | Correction | Bibtex | AbstractThis paper sheds light on two age-old questions of interest group behavior: how have interest group coalition strategies changed over time and which factors determine whether interest groups work together? Through the creation of a new network measure of interest group coalitions based on cosigner status to United States Supreme Court amicus curiae briefs, we illuminate the central players and overall characteristics of this dynamic network from 1930 to 2009. We present evidence of an increasingly transitive network resembling a host of tightly grouped factions and leadership hub organizations employing mixed coalition strategies. We also model the attribute homophily and structure of the present-day network. We find assortative mixing of interest groups based on industry area, budget, sales and membership.

Keywords: Interest groups, Coalition strategies, Amicus curiae briefs, Social networks, Exponential random graph model

Quality Over Quantity: Amici Influence and Judicial Decision Making. American Political Science Review, 107(3): 1-15 (Janet M. Box-Steffensmeier, Dino P. Christenson and Matthew P. Hitt). Data | Bibtex | AbstractInterest groups often make their preferences known on cases before the U.S. Supreme Court via amicus curiae briefs. In evaluating the case and related arguments, we posit that judges take into account more than just the number of supporters for the liberal and conservative positions. Specifically, judges’ decisions may also reflect the relative power of the groups. We use network position to measure interest group power in U.S. Supreme Court cases from 1946 to 2001. We find that the effect of interest group power is minimal in times of heavily advantaged cases. However, when the two sides of a case are approximately equal in the number of briefs, such power is a valuable signal to judges. We also show that justice ideology moderates the effect of liberal interest group power. The results corroborate previous findings on the influence of amicus curiae briefs and add a nuanced understanding of the conditions under which the quality and reputation of interest groups matter, not just the quantity.

Keywords: Interest groups, Supreme Court decisions, Amicus curiae briefs, Social networks, Eigenvector centrality, Ideology