Armin Seimel

This Data Descriptor releases an election-year panel of economic left-right and cultural cosmopolitan–traditionalist party positions for 708 parties in 65 countries from 1944 to 2025. The panel supports comparative analyses connecting party-level ideological supply to elections, regions, voters, institutions, or political economy over long periods. Estimates are produced by a Bayesian dynamic item-response model that places heterogeneous text and expert evidence on a common latent scale and reports posterior uncertainty for every party-election estimate. The model combines the temporal reach of manifesto and media text data with the precision of expert placements by treating expert surveys, manifesto codings, media sentence codings, and historical expert data as noisy item-level signals of underlying party positions. Text counts enter through a two-part hurdle binomial likelihood, aggregate expert means enter through beta-binomial likelihoods, general left-right ratings inform the relationship between dimensions, and party positions evolve through random walks within party segments. Technical validation combines item-response diagnostics, random and party-blocked held-out expert prediction, convergent and discriminant checks, posterior predictive coverage, evidence-composition balance, robustness analyses, and convergence diagnostics.

When did contesting European integration begin to pay off at the ballot box? Historians document that parties contested the European project from its founding, but whether this translated into electoral rewards remains untested across the full post-war period. I address this question through a Bayesian measurement model that estimates party EU contestation intensity by combining the temporal scope of manifesto data with the precision of expert surveys, then linking these estimates to electoral outcomes for 416 parties across 28 European countries from 1945 to 2022. The contestation estimates confirm that elite contestation accompanied European integration throughout its history. Yet the vote analysis reveals that electoral rewards for EU contestation emerged only in the post-Eurocrisis era; earlier treaty periods show no significant relationship between contestation and electoral performance. The supply side of EU contestation has always been present. Only recently has the European public responded at the ballot box.

Various robust communication effects have been identified, but evidence is overwhelmingly based on artificial survey treatments with limited real-world insight. This study conducted a natural experiment on the impact of the European–Turkey statement closing the Balkan route during the 2015/16 European refugee crisis in Germany. Treatment and control groups were identified based on timing to demonstrate the effect on perceptions of the crisis, asylum attitudes, and policy preferences. Effects are largest immediately following the announcement but decline rapidly, showing political communication can significantly change opinion within a limited time frame.

The empirical evidence on the link between elite polarization and democracy is mixed, with scholars finding elite polarization increases turnout but decreases democratic satisfaction. This study presents a new individual-level measure of perceived elite polarization that reveals the complexities of individual perceptions beyond macro elite polarization. Results confirm that higher perceptions of elite polarization can engage citizens but reduce satisfaction with democracy. However, higher perceptions also decrease the likelihood of people being simultaneously satisfied with democracy and voting, indicating high perceived elite polarization can be detrimental to democracy.