When working with panel data, many researchers wish to estimate the direct effects of time-varying factors on future outcomes. However, when a baseline treatment affects both the confounders of further stages of the treatment and the outcome, the estimation of controlled direct effects (CDEs) using traditional regression methods faces a bias trade-off between confounding bias and post-treatment control. Drawing on research from the field of epidemiology, in this article I present a marginal structural modeling (MSM) approach that allows scholars to generate unbiased estimates of CDEs. Further, I detail the characteristics and implementation of MSMs, compare the performance of this approach under different conditions, and discuss and assess practical challenges when conducting them. After presenting the method, I apply MSMs to estimate the effect of wealth in childhood on political participation, highlighting the improvement in terms of bias relative to traditional regression models. The analysis shows that MSMs improve our understanding of causal mechanisms especially when dealing with multi-categorical time-varying treatments and non-continuous outcomes.

Despite widespread belief in the efficacy of statutes prohibiting discrimination in public accommodations, including protections for the use of privately provided yet publicly available services such as transportation, hotels, and restaurants, we lack causal estimates of the impacts of these statutes on the well-being of those they are designed to protect. We leverage the US Supreme Court's 1883 strike of the public accommodations provisions in the Civil Rights Act of 1875, along with variation in state-level statutes, to identify the impact of the Act's public accommodations provisions. Using a panel of repeated geo-located medical exams of US Colored Troops (USCT) and white Union Army veterans, and a series of difference-in-differences, geographic regression discontinuity, and placebo designs, estimates consistently suggest that the Court's ruling led to meaningful weight losses for USCT veterans in states without state-level public accommodations statutes. These findings suggest that statutes prohibiting discrimination in public accommodations can have significant positive impacts on the well-being of those they are designed to protect.

What explains variation in tax progressivity before World War I? I argue that trade politics shaped the emergence of progressive taxation. If labor could provide a useful ally, trade policy coalitions meant compromise on redistributive demands: progressive taxes, especially where inequality was lower. In time-series cross-sectional analysis, I find that trade interest proximity between labor and elites was associated with more progressive taxation in ten European countries between 1870 and 1913 under conditions of low inequality. The coalition and compromise mechanism is evident in sub-national evidence from Britain. Where constituency interests favored free trade, Liberal–Labour electoral alliance was more likely in 1906, and the local MP was more likely to support the 1909 “People's Budget” for progressive taxation.

A common causal identification strategy in political science is selection on observables. This strategy assumes one observes a set of covariates that is, after statistical adjustment, sufficient to make treatment status as-if random. Under adjustment methods such as matching or inverse probability weighting, coefficients for control variables are treated as nuisance parameters and are not directly estimated. This is in direct contrast to regression approaches where estimated parameters are obtained for all covariates. Analysts often find it tempting to give a causal interpretation to all the parameters in such regression models—indeed, such interpretations are often central to the proposed research design. In this paper, we ask when we can justify interpreting two or more coefficients in a regression model as causal parameters. We demonstrate that analysts must appeal to causal identification assumptions to give estimates causal interpretations. Under selection on observables, this task is complicated by the fact that more than one causal effect might be identified. We show how causal graphs provide a framework for clearly delineating which effects are presumed to be identified and thus merit a causal interpretation, and which are not. We conclude with a set of recommendations for how researchers should interpret estimates from regression models when causal inference is the goal.

Amazon's Mechanical Turk is widely used for data collection; however, data quality may be declining due to the use of virtual private servers to fraudulently gain access to studies. Unfortunately, we know little about the scale and consequence of this fraud, and tools for social scientists to detect and prevent this fraud are underdeveloped. We first analyze 38 studies and show that this fraud is not new, but has increased recently. We then show that these fraudulent respondents provide particularly low-quality data and can weaken treatment effects. Finally, we provide two solutions: an easy-to-use application for identifying fraud in the existing datasets and a method for blocking fraudulent respondents in Qualtrics surveys.

In the context of recent economic and financial crisis in Europe, questions about the power of the core executive to control fiscal outcomes are more important than ever. Why are some governments more effective in controlling spending while others fall prey to excessive overspending by individual cabinet ministers? We approach this question by lifting the veil of collective cabinet responsibility and focusing on intra-cabinet decision-making around budgetary allocation. Using the contributions of individual cabinet members during budget debates in Ireland, we estimate their positions on a latent dimension that represents their relative levels of support or opposition to the cabinet leadership. We find some evidence that ministers who are close to the finance minister receive a larger budget share, but under worsening macro-economic conditions closeness to the prime minister is a better predictor for budget allocations. Our results highlight potential fragility of the fiscal authority delegation mechanism in adverse economic environment.

Political preferences in the United States are highly correlated with population density, at national, state, and metropolitan-area scales. Using new data from voter registration records, we assess the extent to which this pattern can be explained by geographic mobility. We find that the revealed preferences of voters who move from one residence to another correlate with partisan affiliation, though voters appear to be sorting on non-political neighborhood attributes that covary with partisan preferences rather than explicitly seeking politically congruent neighbors. But, critically, we demonstrate through a simulation study that the estimated partisan bias in moving choices is on the order of five times too small to sustain the current geographic polarization of preferences. We conclude that location must have some influence on political preference, rather than the other way around, and provide evidence in support of this theory.

The level of legislative turnover in a polity can have significant political consequences. Low turnover may increase the number of legislators who are out of touch with constituents, while high turnover can limit a legislature’s ability to fulfill its duties. Focusing on separation of powers arrangements, a factor overlooked by previous studies, we identify institutional conditions that affect turnover. When the executive and legislature are equally responsible for budgetary outcomes, we argue, this creates ambiguous contexts, leaving voters more likely to re-elect incumbents, thereby lowering turnover. We test our predictions using US state-level data.

In this paper, we show that state stability exhibits a persistent and robust non-monotonic relationship with economic development. Based on observations in Europe spanning from 1 to 2000 AD, regions that have historically experienced either short- or long-duration state rule on average lag behind in their local wealth today, while those that have experienced medium-duration state rule fare better. These findings support the argument that both an absence as well as an excess of state stability are bad for economic development. State instability hinders investment for growth, while too much stability is likely indicative of elite capture and subsequent stagnation of innovation.

This article examines online recruitment via Facebook, Mechanical Turk (MTurk), and Qualtrics panels in India and the United States. It compares over 7300 respondents—1000 or more from each source and country—to nationally representative benchmarks in terms of demographics, political attitudes and knowledge, cooperation, and experimental replication. In the United States, MTurk offers the cheapest and fastest recruitment, Qualtrics is most demographically and politically representative, and Facebook facilitates targeted sampling. The India samples look much less like the population, though Facebook offers broad geographical coverage. We find online convenience samples often provide valid inferences into how partisanship moderates treatment effects. Yet they are typically unrepresentative on such political variables, which has implications for the external validity of sample average treatment effects.

Existing arguments across political science posit that parties in government use domestic and international institutions to lock in their own policy preferences by tying the hands of successors. I demonstrate that these arguments contrast with the assumption of office-seeking parties and therefore portray an incomplete picture of the incentives of governments. The paper emphasizes the trade-off between implementing policy preferences, on the one hand, and exploiting partisan differences for electoral success, on the other hand: locking in a policy takes an issue off the table, but it also undermines a party’s ability to leverage differences to the opposition in elections. Because office-seeking parties need to take into account these electoral consequences, they have a disincentive to tie their successors’ hands. I advance this argument in the context of the establishment of independent central banks, provide empirical evidence, and suggest implications for the literature on international institutions.

I study the effects of direct democracy on economic policy in a novel setting. In Spain, national law determines that municipalities follow either direct or representative democracy, depending on their population size. Using a fixed-effect regression discontinuity design, I find that direct democracy leads to a smaller government, reducing public spending by around 8 percent. Revenues decrease by a similar amount and, therefore, there is no effect on budget deficits. These findings can be explained by a model in which direct democracy allows voters to enforce lower special-interest spending. I provide several additional results and discuss alternative mechanisms.

While party splits are a relatively frequent phenomenon in many new and established democracies, the systematic empirical research on electoral competition after schisms is limited. The analysis of more than 200 splits across 25 European countries in the post-war period addresses this gap in the research. The study shows that the vote shares of rump and splinter parties in the first election after fission are related to their membership strength and the share of splinter legislators. This relationship is present in both Western Europe and Central and Eastern Europe. Additionally, economic growth affects the support of rump parties that hold government office while party system fragmentation and party funding regulations correlate with the electoral performance of splinter parties.

Instrumental variable (IV) methods are widely used to address endogeneity concerns. Yet, a specific kind of endogeneity – spatial interdependence – is regularly ignored. We show that ignoring spatial interdependence in the outcome results in asymptotically biased estimates even when instruments are randomly assigned. The extent of this bias increases when the instrument is also spatially clustered, as is the case for many widely used instruments: rainfall, natural disasters, economic shocks, and regionally- or globally-weighted averages. Because the biases due to spatial interdependence and predictor endogeneity can offset, addressing only one can increase the bias relative to ordinary least squares. We demonstrate the extent of these biases both analytically and via Monte Carlo simulation. Finally, we discuss a general estimation strategy – S-2SLS – that accounts for both outcome interdependence and predictor endogeneity, thereby recovering consistent estimates of predictor effects.

I propose a unified explanation for parties' joint policy and emphasis decisions which bridges saliency theory and spatial analyses of party campaigns. Party platforms are anchored by the policy preferences of activists, core supporters and target voters, leading parties to disproportionately emphasize issues where their policies are popular with all key constituencies. However, which voters a party targets relates to its historical electoral performance (“party size”). Traditionally successful (“major”) parties emphasize issues where the policies preferred by activists and core supporters are generally popular, but smaller (“minor”) parties emphasize issues where their preferred policies may be unpopular but are distinctive. Using recent European data and various empirical strategies, I show that this account has significant explanatory power beyond existing party typologies and theories of issue selection.

We present an intra-party account of electoral reform, contrasting the incentives of legislators (MPs) with those of party leaders. We develop our argument along the switch to proportional representation (PR) in early 20th century Europe. District-level electoral alliances allowed bourgeois MPs to counter the “socialist threat” under the electoral systems in place. PR was thus unnecessary from the seat-maximizing perspective that dominates previous accounts—intra-party considerations were crucial: candidate nomination and legislative cohesion. We show our argument to hold empirically both for the prototypical case of Germany, 1890–1920, using encompassing district-level data on candidatures, elections, electoral alliances, roll call votes and a series of simulations on reform effects; and for the implementation of electoral reforms in 29 countries, 1900–31.

Local politicians are often expected to mobilize voters on behalf of copartisan candidates for national office. Yet this requirement is difficult to enforce because the effort of local politicians cannot be easily monitored and the promise of rewards in exchange for help is not fully credible. Using a formal model, we show that the incentives of local politicians to mobilize voters on behalf of their party depend on the proportion of copartisan officials in a district. Having many copartisan officials means that the party is more likely to capture the district, but the effort of each local politician is less likely either to be noticed by higher-level officials or to make a difference on the election outcome, thus discouraging lower-level officials from exerting effort. We validate these claims with data from federal elections in Mexico between 2000 and 2012. In line with the argument, the results show that political parties fail to draw great mobilization advantages from simultaneously controlling multiple offices.

Do elections motivate incumbent politicians to serve their voters? In this paper, we use millions of service requests placed by residents in US cities to measure constituency responsiveness. We then test whether an unusual policy change in New York City, which enabled city councilors to run for three rather than two terms in office, improved constituency responsiveness in previously term-limited councilors’ districts. Using difference-in-differences, we find robust evidence for this. Taking advantage of differential timing of local election races in New York City and San Francisco, we also find late-term improvements to responsiveness in districts represented by reelection-seeking incumbents. Elections improve municipal services, but also create cycles in constituency responsiveness. These findings have implications for theories of representative democracy.

What attracts voters to far-right parties? Emphasizing the repercussions of far-right parties' past achievements on the mobilization of voters' electoral demand, this paper develops an argument of context-dependent strategic far-right voting. Far-right parties seek to mobilize on a combination of demand for nativist policies and anti-establishment protest sentiment. Their capacity of doing so, however, critically depends on the strategic incentives they supply. My findings from a comparative analysis based on six waves of the European Election Study show that far-right parties' past attainment of legislative strength boosts the credibility of their policy appeal and broadens the scope of their protest appeal whereas their participation in government jeopardizes their capacity to mobilize on popular discontent.

There are a number of observed gender differences in the frequency of political discussion, perceived levels of expertise, and importantly, openness to persuasion. This article explores the consequences of these differences for political choices. Given the difficulty in separating influence from homophily with observational data, this paper relies on a group-based experiment. Results suggest that when selecting between candidates, women are more likely to accept information from others, even if the information in the signals is not helpful. Men, on the other hand, often ignore outside signals in favor of sticking with their own choices even when outside signals would be helpful to their decision-making. A reanalysis of a previously published experiment on social communication leads to similar gender differences.