I am a Data Scientist at Nationwide and visiting scholar in the Department of Political Science at The Ohio State University. I earned my Ph.D. at OSU, focusing on political methodology and comparative politics. Prior to being at OSU, I earned an M.A. in political science from Boston College and my B.A. in economics and German studies from Lewis & Clark College.
In my methods research, I focus on models for network analysis, particularly latent space models and advanced exponential random graph models, as well as the computational aspects of estimating these models. I have also done research on causal inference in the context of natural experiments (instrumental variables and regression discontinuity designs). In my applied research, I have extensive experience using multi-level and mixed effects models, event history, and time-series methods.
How Strong is Strong Enough? Strengthening
Instruments through Matching and Weak Instrument Tests
(with Luke Keele). Annals
of Applied Statistics.
Abstract: In a natural experiment, treatment assignments are made through a haphazard process that is thought to be as-if random. In one form of natural experiment, encouragement to accept treatment rather than treatments themselves are assigned in this haphazard process. This encouragement to accept treatment is often referred to as an instrument. Instruments can be characterized by different levels of strength depending on the amount of encouragement. Weak instruments that provide little encouragement may produce biased inferences, particularly when assignment of the instrument is not strictly randomized. A specialized matching algorithm can be used to strengthen instruments by selecting a subset of matched pairs where encouragement is strongest. We demonstrate how weak instrument tests can guide the matching process to ensure that the instrument has been sufficiently strengthened. Specifically, we combine a matching algorithm for strengthening instruments and weak instrument tests in the context of a study of whether turnout influences party vote share in US elections. It is thought that when turnout is higher, Democratic candidates will receive a higher vote share. Using excess rainfall as an instrument, we hope to observe an instance where unusually wet weather produces lower turnout in an as-if random fashion. Consistent with statistical theory, we find that strengthening the instrument reduces sensitivity to bias from an unobserved confounder.
Modeling Unobserved Heterogeneity in
Social Networks with the Frailty Exponential Random Graph
Box-Steffensmeier and Dino Christenson)
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.
- Inferential Network Analysis (with Skyler Cranmer and Bruce Desmarais). Under contract with Cambridge University Press.
- The Cheap Seats:
Party Development and Local Electoral Reform in Poland
Abstract: In this paper, I investigate the link between local electoral institutions and party build- ing in new democracies. I argue that, as is the case with national electoral systems, local institutions can play an important role in party system institutionalization. Specifi- cally, by shaping the incentives for local politicans to join national parties and for national parties to get involved in local politics, different local electoral institutions can inhibit or encourage national party penetration into local politics. I support this argument with an analysis of an unique electoral system discontinuity in Poland. My analysis, which applies a regression discontinuity design approach, shows that a change from plurality election rules to proportional representation had a significant effect on national party performance in local elections in Poland.
What is the Value of
Left and Right? Party Competition and Political Ideology in East-Central
Europe (with Paul
DeBell). Under review.
Abstract: What does left-right self-identification tell us about voters, and how do these ideological labels come to have meaning? We compare self-placement across 23 countries in Eastern and Western Europe. Comporting with previous studies, we find consistency between psychological traits and left-right self-identification in established democracies, but variability in young post-communist democracies. We then demonstrate a link between elite appeals and the meaning of left and right held by voters. Matching elite appeals to left-right self-placement in the Czech Republic, Hungary, Poland, and Slovakia, we show that messages espoused by political parties determine voter ideological orientation as a function of whether these messages are congruent with (or repugnant to) a voter's own psychological orientations. This research provides important insight into how ideology comes to have meaning for voters, showing that psychological motives are expressed by ideology in different ways across political contexts.
The Latent Path
Model for Dynamic Social Networks with an Application to Party
Switching in Poland
Abstract: High rates of party switching by politicians is often expected to inhibit party system institutionalization by reducing democratic representation, accountability, and the heuristic value of party labels. However, in new democracies, where social connections and party labels are weak, switching may allow politicians the flexibility to sort themselves into more cohesive groups, ultimately contributing to an increased likelihood of long-term party system stability. To investigate the phenomenon of party switching more closely, this paper develops a new latent variable model suitable for analyzing dynamic network data. The proposed latent path model is a natural extension of the latent space model for static networks developed by Hoff, Raftery, and Handcock (2002) and is in the spirit of the dynamic network model of Ward, Ahlquist, and Rozenas (2013). An application of the model to party switching in Poland, which has seen more than 1,100 instance of party switching since the first democratic election in 1991, shows that switching during the first five parliamentary terms resulted in greater ideological coherence of parties and that a core group of 199 long-serving MPs has been at the leading edge of this convergence. This counterintuitive result suggests party switching may sometimes play a more constructive role in party system institutionalization than typically realized, while it also suggests that the Polish party system may be developing the foundations of a strong and stable party system.
- boolean3: a reimplementation of the boolean package in R. Provide multiprocessor support, improve performance, and the extend capabilities of the package (supervised by Bear Braumoeller). Websites: CRAN, GitHub.
- iv_sens: an implementation of Rosenbaum's instrumental variable sensitivity analysis for causal inference. Available in the rbounds package for R (with Luke Keele). Website: CRAN.