Comparing Party Positions in a European Multidimensional Political Space: a Cross-Validation of the EU Profiler/euandi Longitudinal Dataset, 2009-2019

Data sources measuring and mapping the spatial positioning of political parties in European political systems have been proliferating over recent years. Moreover, many of these data resources now comprise multiple waves, allowing for cross-time longitudinal comparisons of parties’ positions. Taking parties as the unit of analysis, these datasets rely on diverse sources to map parties’ positions on the political space, including manifesto analysis, expert judgements and survey data tapping voters’ party placements. More recently, voting advice applications have also become an increasingly popular instrument to accurately map party positioning in multidimensional political spaces. This paper provides a comprehensive report of the EU Profiler/euandi longitudinal dataset and examines its reliability through cross-validation with additional data sources measuring parties’ spatial positioning in a multidimensional European political space. The EU Profiler/euandi longitudinal dataset stems from three voting advice applications fielded during the campaigns of the European Parliament Elections of 2009, 2014 and 2019, providing data on over 400 unique political parties across 28 European Union member states. Parties’ positions were coded by teams of country experts in direct interaction with political parties, who have been asked to self-position with regard to policy issues. We detail the scope, empirical focus and question wording of the policy statements used in the several waves of the EU Profiler/euandi longitudinal dataset, while substantiating the construction of the analytical dimensions. Next, we cross-validate the EU Profiler/euandi longitudinal dataset with three established datasets to measure party positions in Europe: the Comparative Manifesto Project (CMP), the Chapel Hill Expert Survey (CHES) and the Voter Study of the European Election Studies (EES). This strategy aims at assessing the inter-reliability of measures of party positioning deriving from pure expert surveys, party electoral manifestos, voter surveys and voting advice applications. Parties’ positions are analysed and compared on the Cultural liberal-conservative and Socioeconomic left-right dimensions, as well as on Pro/Anti European Union, in the 2009, 2014 and 2019 European Parliament Elections. We also explore a number of sub-dimensions more directly tapping European foreign/defense policy views, Immigration, Green/ecological issues and Liberal/Social values. By adopting a longitudinal focus, using multiple waves of these data sources, we are able to track changes in party positioning across time within and across datasets. Our results attest the reliability of the EU Profiler/euandi trend file vis-à-vis remaining data sources – while offering tentative interpretations for deviations encountered –, demonstrating the validity of party positioning measurements inferred from this novel dataset.