In this article, we examine party positions on sovereignty issues in European countries based on an analysis of party supply. First, we develop an index of sovereignism reflecting the multidimensional articulation and differentiated emphasis put by parties on sovereignist issues. By applying the index to Chapel Hill Expert Survey (CHES) data, the analysis maps all EU member states. Second, we integrate in the analysis party- and country-level data (including the orientations of domestic public opinion). Through multivariate regression analysis we show how party ideology, contextual factors and public mood favoured the spread of party-based sovereignism in European countries.

This article introduces new quantitative fine-tuned indicators to objectively measure political parties’ preferences on gender issues. We assess the validity and reliability of these new empirical indicators by analyzing the relationship between ideology and gender positions in decentralized Spain. Using data collected by the Regional Manifestos Project, which for the first time has incorporated a fully fledged gender domain into its coding scheme for content analysis of regional manifestos, we analyze parties’ gender positions on four fundamental dimensions: welfare and the labor market, violence, representation, and values and identity. The results suggest that there is a persistent left-right divide on the last three dimensions: Spanish left-wing parties score significantly higher than right-wing and regionalist parties. However, ideology does not drive parties’ gender positions on welfare and labor market policies; support for gender equality policies on this dimension is so widespread that it can be considered a “valence issue”—all parties, irrespective of their ideology, endorse the same (positive) position.

Social democratic parties have experienced considerable electoral decline recently, which has often been attributed to their rightward policy movement. This paper advances this literature by examining who benefits from this moderation strategy and who is abandoning the social democrats. It does so by analyzing aggregate-level election results and individual-level Comparative Study of Electoral Systems data, on a sample of 21 advanced democracies, over 327 elections, from 1965 to 2019. I find little support for the assertion that social democrats are defecting to one party. However, in agreement with the spatial theory of party competition, results reveal that the radical left increasingly and significantly benefit from social democratic economic rightward positions, which is magnified when combined with rightward sociocultural positions. This predominantly occurs because left-leaning voters migrate to the radical left. The findings provide notable ramifications for party strategy and contribute to explanations for the rise of challenger parties, at the expense of mainstream parties.

We develop a new measure of party position based on a scaling of ideology tags supplied in infoboxes on political parties’ Wikipedia pages. Assuming a simple model of tag assignment, we estimate the locations of parties and ideologies in a common space. We find that the recovered scale can be interpreted in familiar terms of “left versus right.” Estimated party positions correlate well with ratings of parties’ positions from extant large-scale expert surveys, most strongly with ratings of general left–right ideology. Party position estimates also show high stability in a test–retest scenario. Our results demonstrate that a Wikipedia-based approach yields valid and reliable left–right scores comparable to scores obtained via conventional expert coding methods. It thus provides a measure with potentially unlimited party coverage. Our measurement strategy is also applicable beyond Wikipedia.

European mainstream right parties are increasingly choosing to include radical right parties in coalition governments or other types of stable and committed cooperation. How does this cooperation affect voters’ perceptions of party positions? This article examines whether coalition signals have a significant impact on voters’ perceptions of the specific policy issues that were at stake in the bargaining process. More specifically, does the issue ownership of the radical right cause voters to perceive mainstream parties as radicalizing on immigration issues pertaining to asylum and multiculturalism? I compare the perceptions of Dutch parties before and after two coalition formations that (formally and informally) involved a radical right party: the coalition with the List Pim Fortuyn in 2002 and the support agreement with the Freedom Party in 2010. Furthermore, I examine the long-term effects of the Danish mainstream right government's reliance on the support of the radical right Danish People's Party in 2001–11.

Recent research on electoral behavior has suggested that policy-informed vote choices are frequently obstructed by uncertainty about party positions. Given the significance of clear and distinct party platforms for meaningful representation, several studies have investigated the conditions under which parties are perceived as ambiguous. Yet previous studies have often relied on measures of perceived positional ambiguity that are fairly remote from the concept, casting doubt on their substantive conclusions. This article introduces a statistical model to estimate a comprehensive measure of perceived ambiguity that incorporates the two principal factors: non-positions and positional inconsistency. The two-faces model employs issue perceptions in an item response framework to explicitly parametrize the perceived ambiguity of party positions. The model is applied to data from the Chapel Hill Expert Survey and subsequently associated with party characteristics that drive perceptions of party ambiguity. The results suggest that (a) there are notable differences between the proposed and competing measures, highlighting the need to be mindful of the intricacies of political information processing in research on perceptions of ambiguity and (b) involuntary ambiguity might be an underexplored explanation for unclear party perceptions.

Recent work has pioneered the use of expert surveys to estimate cross-national party positions in a common ideological space. In this paper, we report findings from an original dataset designed to evaluate bridging strategies between European and American party placements. Specifically, we compare the use of “anchoring vignettes” (fictional party platforms) with an alternative approach that asks comparativist scholars who live in the US (whom we call transatlantic or TA experts) to place parties and parties in their country of expertise on a series of issues scales. The results provide an optimistic assessment of the ability of TA experts to serve as valid bridges across the Atlantic. The resulting cross-comparable estimates of party positions show instances of both convergence and divergence between American and European party systems, including parallels between systems on the cross-cutting issue of international economic integration.

Like many party systems across Western Europe, the Dutch party system has been in flux since 2002 as a result of a series of related developments, including the decline of mainstream parties which coincided with the emergence of radical right-wing populist parties and the concurrent dimensional transformation of the political space. This article analyses how these challenges to mainstream parties fundamentally affected the structure of party competition. On the basis of content analysis of party programmes, we examine the changing configuration of the Dutch party space since 2002 and investigate the impact of these changes on coalition-formation patterns. We conclude that the Dutch party system has become increasingly unstable. It has gradually lost its core through electoral fragmentation and mainstream parties’ positional shifts. The disappearance of a core party that dominates the coalition-formation process initially transformed the direction of party competition from centripetal to centrifugal. However, since 2012 a theoretically novel configuration has emerged in which no party or coherent group of parties dominates competition.