Jacob M. Montgomery

Ensemble Predictions of the 2012 US Presidential Election

or more than two decades, political scientists have created statistical models aimed at generating outof-sample predictions of presidential elections. In 2004 and 2008, PS: Political Science and Politics published symposia of the various forecasting models prior to Election Day. This exercise serves to validate models based on accuracy by garnering additional support for those that most accurately foretell the ultimate election outcome. Implicitly, these symposia assert that accurate models best capture the essential contexts and determinants of elections. In part, therefore, this exercise aims to develop the “best” model of the underlying data generating process. Scholars comparatively evaluate their models by setting their predictions against electoral results while also giving some attention to the models’ inherent plausibility, parsimony, and beauty. Our approach is different. Rather than creating the best model or theory, instead we create an ensemble prediction of the upcoming election. We combine the intuition, theories, and concepts implicit in all of the forecasting models presented in this symposium to make an accurate out-of-sample prediction. Without arbitrating between models and theories, we aim to aggregate them solely with an eye toward increasing our chances of getting it right. To do this, we rely on the models presented in this issue. We believe that each model captures an important set of insights about US elections. Our approach combines those insights into a single ensemble prediction. For our purposes, the theoretical differences between the models are irrelevant. All that matters is that each provides predictions for previous elections that we can use to evaluate their accuracy. We then weight each forecast by its previous performance and combine them to create the most accurate out-of-sample forecast possible that also captures the uncertainty and diversity inherent in these models.

Static Stability and Evolving Constraint Preference Stability and Ideological Structure in the Mass Public

Prominent accounts of public opinion argue that citizens’ preferences are unstable, with stated desires on policies varying wildly from survey to survey, and ideologically incoherent, with preferences on multiple policies evidencing little or no structure. In the aggregate, these findings suggest that many voters are not capable of fulfilling their normative role in the democratic system. In this article, we challenge this conventional view and argue that the apparent instability and incoherence among the public are both overstated and outdated. Using panel surveys from the 1970s, 1990s, and 2010s, we conduct a multi-trait multi-method (MTMM) confirmatory factor analysis of citizen preferences in multiple issue areas. Our results reveal a surprising degree of preference stability in all three time periods across many policy domains. Furthermore, our results reveal increasing levels of ideological thinking over time and that these patterns of stability and coherence hold across subpopulations defined by levels of sophistication.

The Effects of Congressional Staff Networks in the U.S. House of Representatives

Standard accounts of legislative behavior typically neglect the activities of professional staff, who are treated as extensions of the elected officials they serve. However, staff appear to have substantial independent effects on observed levels of legislator productivity and policy preferences. In this article, we use a novel data set of comprehensive longitudinal employment records from the US House of Representatives to estimate the effects of congressional staff on legislative behavior. Specifically, results from a series of heteroskedastic Bayesian spatial autoregressive models indicate that members of Congress who exchange important staff members across congresses are more similar in their legislative effectiveness and voting patterns than we would otherwise expect. These findings suggest that scholars should reconsider the role of staff in the legislative process.

Does Public Financing Affect Judicial Behavior? Evidence From the North Carolina Supreme Court

Many observers are concerned that campaign contributions could affect the decisions of elected judges. However, the empirical correlation between contributions and judicial decisions is consistent with two different explanations of judicial behavior: (a) money influences judges or (b) contributors choose to support candidates with a similar philosophical or legal perspective. In this article, we take advantage of North Carolina’s shift to a voluntary public finance system for state Supreme Court candidates to obtain more credible estimates of the contributions–behavior relationship. Applying a difference-in-differences research design, we provide evidence that justices who opted into public financing became relatively less favorable toward attorney donors. We also find partial support for our hypothesis that participating justices became more moderate in their voting patterns. Taken together, these findings suggest that public financing reduced responsiveness to donors among participating justices.

Revisiting white backlash: Does race affect death penalty opinion?:

Peffley and Hurwitz’s article “Persuasion and resistance: Race and the death penalty in America” is an influential study demonstrating the effects of race on death penalty attitudes. White respondents were found to increase their approval for capital punishment when informed that it disproportionately affects African-Americans. We present results from two studies, including one conducted on a nationally representative sample, that fail to find support for this finding. Our first study, which was conducted on Amazon Mechanical Turk, consists of an exact replication as well as an additional manipulation that strengthens the treatment by adding information about a specific black (versus a white) defendant to the stimulus. However, we fail to elicit the backlash effect found in the original study using either manipulation despite having nearly three times the sample size. These findings are mirrored by replication data from a Time-sharing Experiments for the Social Sciences survey that closely replicates Peffley and Hurwitz’s race framing treatment. The results from these studies suggest that the relationship between racial stimuli and death penalty support has changed since the original study, that racial backlash effects in this policy domain are not as robust as previously assumed, or both.

Party Identification in the Age of Obama: Evidence on the Sources of Stability and Systematic Change in Party Identification from a Long-Term Panel Survey

Political scientists have long disagreed about the nature of individual-level change in party identification. While some scholars conclude that party identification is a stable identity—attributing changes in individual responses to measurement error—others show that aggregate party identification responds systematically to short-term forces such as presidential approval. In this article, we use a unique long-term panel measuring party identification twenty times in the 2011–2016 period to support a subtle compromise between these competing claims. We show that individual-level party identification changes systematically over time even after accounting for measurement error and that this change is related to short-term evaluations of the parties and the president. However, although such change exists, it is modest in the medium term and more common among specific subsets of respondents. Finally, we show that that these findings are robust to numerous alternative modeling strategies. We believe that our analysis provides the most systematic examination to date of individual-level changes in party identification.

Political Participation and the 'Feeling of Doing': The Causes and Consequences of Perceptions of Political Control

Perceptions of political control (POPC) is a set of subjective beliefs about the effectiveness of specific actions in achieving desired political outcomes and how capable individuals feel in executing these strategies. We argue that participation in the political system, especially successful participation, fosters these control beliefs. POPC in turn affects how people understand their role in the political world and their reasoning in making political decisions. Using data from a two-wave national survey and a novel experiment, we show that the POPC is distinct from and superior to traditional measures of political efficacy and trust due to its stronger theoretical foundations. Further, as our theory suggests, we show that POPC increases with successful political participation and that individuals with higher POPC are more likely to attribute political outcomes to their personal actions and to ignore information implying that the effectiveness of their actions is conditioned by the political environment.

Why John Aldrich

John Aldrich is a positive scientist—in both the scholastic and colloquial sense. A progeny of the Rochester school, Aldrichs research displays a commitment to the tenets of positive political theory. He derives internally consistent propositions and subjects those claims to empirical testing, all in an attempt to explain scientifically phenomena and institutions at the heart of democratic theory. As a mentor and builder of academic institutions, Aldrich has shown unswerving kindness, modesty, and a commitment to foster new generations of political scientists. He is a positive influence on his students, his colleagues, and the political science discipline at large.