{"id":17,"date":"2024-06-18T18:44:07","date_gmt":"2024-06-18T18:44:07","guid":{"rendered":"https:\/\/jellekoedam.com\/?page_id=17"},"modified":"2025-10-14T09:45:24","modified_gmt":"2025-10-14T09:45:24","slug":"publications","status":"publish","type":"page","link":"https:\/\/jellekoedam.com\/?page_id=17","title":{"rendered":"Publications"},"content":{"rendered":"\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1086\/736578\" target=\"_blank\" rel=\"noreferrer noopener\">A global scale of economic left-right party positions: cross-national and cross-expert perceptions of party placements<\/a>\u201d (with Nicol\u00e1s de la Cerda, Ryan Bakker, et al.),<br><em>Journal of Politics<\/em> (2025).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>We examine the cross-national comparability of expert placements of political parties on the economic left-right dimension using a novel dataset combining data from Europe, Latin America, Australia, Israel, Canada, and the United States. Using anchoring vignettes and Bayesian Aldrich-McKelvey Scaling (BAM), we assess evidence of geographic and expert-level differential item functioning (DIF) in how experts interpret the left-right scale. We find statistically significant but substantively small variations in how experts perceive party positions cross-nationally, particularly in terms of directional bias and the spread of their ideological placements. While the correlation between \u201craw\u201d survey scores and DIF-corrected estimates is high (0.992), we observe meaningful deviations for individual parties, with larger discrepancies between rather than within regions. These results indicate that the economic left-right dimension exhibits broad consistency in expert understanding across countries, yet researchers should still exercise caution when making cross-national comparisons, particularly across regions where expert perceptions show greater variation.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1017\/S0007123424000474\" target=\"_blank\" rel=\"noreferrer noopener\">Multidimensional party polarization in Europe: Cross-cutting divides and effective dimensionality<\/a>\u201d (with Garret Binding and Marco Steenbergen),<br><em>British Journal of Political Science<\/em> (2025).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ideological polarization between political parties is essential for meaningful electoral competition, but at its extreme can strain democratic functioning. Despite a widespread recognition that multiple divides structure contemporary party polarization in Europe, its prevailing conceptualization and measurement remain one-dimensional. To resolve this tension, we introduce a novel, multidimensional approach to party polarization. Our main focus is on whether different ideological divides reinforce or crosscut each other. We calculate the effective dimensionality of a policy space using the correlation matrix of parties\u2019 positions, which accounts for how the dimensions interrelate. Using both artificial data and positional estimates from the Chapel Hill Expert Survey (1999\u20132019), we highlight the advantages of our approach and demonstrate that it is better able to capture the relationship between party polarization and mass partisanship. This study has important theoretical, methodological, and empirical implications for our understanding of polarization and democratic representation in a changing political landscape.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1017\/psrm.2023.16\" target=\"_blank\" rel=\"noreferrer noopener\">The comparative meaning of political space: A comprehensive modeling approach<\/a>\u201d (with Garret Binding and Marco Steenbergen),<br><em>Political Science Research and Methods<\/em>\u00a0(2024).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In latent scaling applications, such as the positioning of political parties, differential item functioning (DIF) may occur because of measurement issues or because of substantive differences in the association between latent and manifest variables. While the first source of DIF has received considerable attention, the second has not, although it is of potential interest to comparative scholars. In this research note, we introduce a novel hierarchical Bayesian item response model that allows us to disentangle different sources of DIF. Drawing on the 2019 Chapel Hill Expert Survey (CHES), we highlight how the same issues are unequally politicized across Western Europe, and how some issues are less ideologically determined than others. Our model can be adapted to alternate settings, allowing researchers to shine a light on variation in, e.g., ideology, issue politicization, or party competition.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1111\/1475-6765.12698\" target=\"_blank\" rel=\"noreferrer noopener\">The ideological profile of the technocratic citizen<\/a>\u201d (with Eri Bertsou and Daniele Caramani),<br><em>European Journal of Political Research<\/em>\u00a0(2024).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A certain type of citizen holds technocratic views. They favour pragmatic problem solving through scientific and technical expertise, and reject party politics for being harmful to the common good. Yet, empirical evidence on the ideological profile of these citizens is fragmented and inconclusive. Using an original survey in Western Europe, Australia and the United States, we test predictions about the left\u2212right alignment of citizens with technocratic attitudes on the economic and cultural dimensions of politics. We argue that technocracy is not antithetical to ideology and that citizens holding technocratic attitudes are not immune to ideological positions. Findings show that technocratic citizens are more economically left-wing than mainstream voters, contrary to common associations of technocracy with neoliberal economic principles. However, they are more centrist than populists. This highlights that, in addition to a representational challenge, technocracy mounts an ideological challenge to party-based representative democracy. In times of cumulative crises, which put democracies under stress with demands for competence and effectiveness, these findings offer insights about the appeal of alternative forms of representation.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1017\/S0008423924000337\" target=\"_blank\" rel=\"noreferrer noopener\">CHES Canada<\/a>\u201d (with Ruth Dassonneville),<br><em>Canadian Journal of Political Science<\/em>\u00a0(2024).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In latent scaling applications, such as the positioning of political parties, differential item functioning (DIF) may occur because of measurement issues or because of substantive differences in the association between latent and manifest variables. While the first source of DIF has received considerable attention, the second has not, although it is of potential interest to comparative scholars. In this research note, we introduce a novel hierarchical Bayesian item response model that allows us to disentangle different sources of DIF. Drawing on the 2019 Chapel Hill Expert Survey (CHES), we highlight how the same issues are unequally politicized across Western Europe, and how some issues are less ideologically determined than others. Our model can be adapted to alternate settings, allowing researchers to shine a light on variation in, e.g., ideology, issue politicization, or party competition.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1080\/01402382.2021.1915659\" target=\"_blank\" rel=\"noreferrer noopener\">A change\u00a0of heart? Analyzing stability and change in European party positions<\/a>\u201c,<br><em>West European Politics<\/em>\u00a0(2022).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Political parties are often assumed to be adaptive, strategic organisations that continuously alter their policy positions to maximise electoral support. However, ideological continuity is an integral part of democratic representation as well. How do parties balance these seemingly conflicting roles? This study combines insights from spatial models of elections and cleavage theory to explain stability and change in European party positions. Embracing the multidimensionality of the policy space, I argue that a party\u2019s reputation and durable party-voter linkages constrain positional change on its more salient, primary dimension. Yet, by remaining ideologically true to its supporters\u2019 key concerns, a party can strategically shift on secondary issues outside of its core agenda. Cross-sectional time series analysis of party positions (1999\u20132019) across fourteen Western European countries confirms this prediction, especially for small to medium-sized and opposition parties. This finding has important implications for our understanding of party strategy and democratic representation.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1016\/j.electstud.2022.102473\" target=\"_blank\" rel=\"noreferrer noopener\">Parties\u2019 voter targeting strategies: What can Facebook ads tell us?<\/a>\u201d (with Simon Stuckelberger),<br><em>Electoral Studies<\/em>\u00a0(2022).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Digital political advertising on social media is an integral part of modern election campaigns. It gives political parties a powerful new tool to target voters, but which voters do they pursue? Tapping into an ongoing debate about party strategy, we examine whether parties seek to maintain their existing demographic and regional strongholds, or whether they aim to expand their voter coalitions. While the (intended) audience of other campaign activities is often unknown, data from the Facebook ads archive provide information on their recipients\u2019 gender, age, and subnational region. Our analysis across five countries, which further brings in recent survey and electoral data, suggests that coalition maintenance is the dominant party strategy for demographic groups. Parties that receive more support from a given gender or age group run ads that reach more members of that demographic group. Consistent with the literature that shows a gender and age gap in voting, left-wing parties are more likely to advertise to women than right-wing parties, and green parties disproportionately reach younger voters. The results for geographic groups are mixed. We do find that parties in majoritarian electoral systems pursue a narrower regional audience than their counterparts in proportional systems. This study is one of the first to explore the potential and limitations of Facebook ad audience data to speak to a targeting literature in need of more comparative research on multiparty systems.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/doi.org\/10.1177\/14651165211027472\" target=\"_blank\" rel=\"noreferrer noopener\">Avoidance, ambiguity, alternation: Position blurring strategies in multidimensional party competition<\/a>\u201c,<br><em>European Union Politics<\/em>\u00a0(2021).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In a multidimensional environment, parties may have compelling incentives to obscure their preferences on select issues. This study contributes to a growing literature on position blurring by demonstrating&nbsp;<em>how<\/em>&nbsp;party leaders purposively create uncertainty about where their party stands on the issue of European integration. By doing so, it theoretically and empirically disentangles the cause of position blurring\u2014parties\u2019 strategic behavior\u2014from its intended political outcome. The analysis of survey and manifesto data across 14 Western European countries (1999\u20132019) confirms that three distinct strategies\u2014avoidance, ambiguity, and alternation\u2014all increase expert uncertainty about a party\u2019s position. This finding is then unpacked by examining for whom avoidance is particularly effective. This study has important implications for our understanding of party strategy, democratic representation, and political accountability.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/www.tandfonline.com\/doi\/full\/10.1080\/17457289.2019.1655647\" target=\"_blank\" rel=\"noreferrer noopener\">Who\u2019s at the helm? When party organization matters for party strategy<\/a>\u201c,<br><em>Journal of Elections, Public Opinion, and Parties<\/em>\u00a0(2019).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Why do parties change their policy positions? A growing literature suggests that the internal balance of power between leaders and activists affects how a party responds to changing environmental incentives. This paper explores when and how party organization matters for party strategy. It argues that a key prediction \u2013 that leadership-dominated and activist-dominated parties are responsive to the positional shifts of the mean voter and the party voter, respectively \u2013 is conditional on two factors, namely a party\u2019s electoral performance and party system polarization. Cross-sectional time series analyses of fifty-five parties in 10 European democracies between 1977 and 2003 confirm that (1) leadership-dominated parties\u2019 responsiveness to the mean voter decreases as their electoral fortunes improve, (2) increases as a party system becomes more polarized, while (3) activist-dominated parties more reliably follow the positional shifts of the party voter. This study\u2019s findings have important implications for our understanding of how intra-party politics influences inter- party competition, and thus democratic representation more generally.<\/li>\n<\/ul>\n\n\n\n<p>\u201c<a href=\"https:\/\/journals.sagepub.com\/doi\/10.1177\/2053168016686915\" target=\"_blank\" rel=\"noreferrer noopener\">Explaining the salience of anti-elitism and reducing political corruption for political parties in Europe with the 2014 Chapel Hill Expert Survey data<\/a>\u201d (with Jonathan Polk, Jan Rovny, Ryan Bakker, Erica Edwards, Liesbet Hooghe, Seth Jolly, Filip Kostelka, Gary Marks, Gijs Schumacher, Marco Steenbergen, Milada Vachudova, and Marko Zilovic),<br><em>Research and Politics<\/em>\u00a0(2017).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>This article addresses the variation of anti-corruption and anti-elite salience in party positioning across Europe. It demonstrates that while anti-corruption salience is primarily related to the (regional) context in which a party operates, anti-elite salience is primarily a function of party ideology. Extreme left and extreme conservative (TAN) parties are significantly more likely to emphasize anti-elite views. Through its use of the new 2014 Chapel Hill Expert Survey wave, this article also introduces the dataset.<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u201cA global scale of economic left-right party positions: cross-national and cross-expert perceptions of party placements\u201d (with Nicol\u00e1s de la Cerda, Ryan Bakker, et al.),Journal of Politics (2025). \u201cMultidimensional party polarization in Europe: Cross-cutting divides and effective dimensionality\u201d (with Garret Binding and Marco Steenbergen),British Journal of Political Science (2025). \u201cThe comparative meaning of political space: A &#8230; <span class=\"more\"><a class=\"more-link\" href=\"https:\/\/jellekoedam.com\/?page_id=17\">[Read more&#8230;]<\/a><\/span><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["entry","page","publish","author-tike","post-17"],"_links":{"self":[{"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/pages\/17"}],"collection":[{"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/jellekoedam.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=17"}],"version-history":[{"count":8,"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/pages\/17\/revisions"}],"predecessor-version":[{"id":72,"href":"https:\/\/jellekoedam.com\/index.php?rest_route=\/wp\/v2\/pages\/17\/revisions\/72"}],"wp:attachment":[{"href":"https:\/\/jellekoedam.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=17"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}