Justin H. Kirkland

Toward a Network Theory of Alliance Formation

We propose a network-based theory of alliance formation. Our theory implies that, in addition to key state and dyad attributes already established in the literature, the evolution of the alliance network from any given point in time is largely determined by its structure. Specifically, we argue that closed triangles in the alliance network—where i is allied with j is allied with k is allied with i — produce synergy effects in which state-level utility is greater than the sum of its dyadic parts. This idea can be generalized to n-state closure, and, when considered along with factors that make dyadic alliance formation more attractive, such as military prowess and political compatibility, suggests that the network will evolve toward a state of several densely connected clusters of states with star-like groupings of states as an intermediary stage. To evaluate our theory, we use the temporal exponential random graph model and find that the roles of our network effects are robustly supported by the data, whereas the effects of non-network parameters vary substantially between periods of recent history. Our results indicate that network structure plays a greater role in the formation of alliance ties than has been previously understood in the literature.

Measurement and theory in legislative networks: The evolving topology of Congressional collaboration

Abstract The examination of legislatures as social networks represents a growing area of legislative scholarship. We examine existing treatments of cosponsorship data as constituting legislative networks, with measures aggregated over entire legislative sessions. We point out ways in which the direct application of models from the social networks literature legislative networks aggregated over entire sessions could potentially obscure interesting variation at different levels of measurement. We then present an illustration of an alternative approach, in which we analyze disaggregated, dynamic networks and utilize multiple measures to guard against overly measure-dependent inferences. Our results indicate that the cosponsorship network is a highly responsive network subject to external institutional pressures that more aggregated analyses would overlook.

Ideological Heterogeneity and Legislative Polarization in the United States

The responsiveness of individual legislators to their constituents creates an indirect electoral connection between the aggregate preferences of citizens and the behavior of legislative parties. In this research, I argue that legislators from moderate districts are the least likely to support their parties and most likely to vote moderately during roll call votes. I also argue that states with low ideological variance among citizens are the most likely to have moderate districts. Thus, states with ideologically heterogeneous populations are more likely to have homogeneous, extreme legislative parties. Using ideal point estimates and measures of party cohesion from state legislative parties, empirical evidence largely supports my expectations.

Hypothesis Testing for Group Structure in Legislative Networks

Scholars of social networks often rely on summary statistics to measure and compare the structures of their networks of interest. However, measuring the uncertainty inherent in these summaries can be challenging, thus making hypothesis testing for network summaries difficult. Computational and nonparametric procedures can overcome these difficulties by allowing researchers to generate reference distributions for comparison directly from their data. In this research, I demonstrate the use of nonparametric hypothesis testing in networks using the popular network summary statistic network modularity. I provide a method based on permutation testing for assessing whether a particular network modularity score is larger than a researcher might expect due to random chance. I then create a simulation study of network modularity and its simulated reference distribution that I propose. Finally, I provide an empirical example of this technique using cosponsorship networks from U.S. state legislatures.

Partisanship and Reciprocity in Cross-Chamber Legislative Interactions

The bicameral nature of most U.S. legislatures implies that it is often in the interest of legislators to collaborate on legislation across chamber lines. In this research, we offer a novel theory of collaboration between upper and lower chamber members in U.S. legislatures. We expect that exogenous characteristics like party, constituency, and joint committee membership characterize collaboration across legislative chambers. Additionally, we expect that endogenous patterns of reciprocity will also characterize choices about cross-chamber collaboration. Using data on cross-chamber bill sponsorship in legislatures in Texas, Colorado, Maine, and Oklahoma, empirical evidence largely corroborates our expectations. Cross-chamber collaborative choices are reciprocal, and reciprocity occurs both within and between parties.

Wallet-Based Redistricting Evidence for the Concentration of Wealth in Majority Party Districts

This article examines the role of wealth in the redistricting process in state legislative contests. I argue that the decision by state redistricting mapmakers to pursue a “seat-swing” or “protection” strategy involves more than just a choice between where to move partisan voters. Redistricting may also allow parties to consider wealth as an additional resource to be concentrated or dispersed across legislative districts. To test this wealth-based hypothesis, I examine state redistricting plans in California and North Carolina. Logistic regression analyses of census block group exchanges between state legislative districts reveal that income plays a significant role in redistricting decisions.

Legislative Party Polarization and Trust in State Legislatures

We argue that citizens’ trust attitudes are inversely related to party polarization because polarization tends to encourage political conflict, which most people dislike. We further posit that partisans trust attitudes are driven by the ideological extremity of the opposing and their own parties for similar reasons. Using roll-call-based estimates of state legislative party polarization and public opinion data collected in 2008, we show strong evidence in favor of our theory: higher levels of party polarization within legislative chambers depresses citizens’ trust in their legislatures. Among partisans, we also find that trust attitudes respond to the ideological extremity of the opposing party but not to a citizen’s own party’s extremity. We further find that as citizens’ interest in politics increases, they react more strongly to polarization when forming their trust attitudes. Finally, partisans become less responsive to the ideological extremity of the opposing party as they become more politically interested.

Ideology, Grandstanding, and Strategic Party Disloyalty in the British Parliament

Strong party discipline is a core feature of Westminster parliamentary systems. Parties typically compel members of Parliament (MPs) to support the party regardless of MPs’ individual preferences. Rebellion, however, does occur. Using an original dataset of MP votes and speeches in the British House of Commons from 1992 to 2015, coupled with new estimations of MPs’ ideological positions within their party, we find evidence that MPs use rebellion strategically to differentiate themselves from their party. The strategy that MPs employ is contingent upon an interaction of ideological extremity with party control of government. Extremists are loyal when their party is in the opposition, but these same extremists become more likely to rebel when their party controls government. Additionally, they emphasize their rebellion through speeches. Existing models of rebellion and party discipline do not account for government agenda control and do not explain these patterns.