{"id":305911,"date":"2026-05-28T10:59:28","date_gmt":"2026-05-28T14:59:30","guid":{"rendered":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/?p=305911"},"modified":"2026-06-02T15:16:06","modified_gmt":"2026-06-02T19:16:06","slug":"appendix-classifying-european-political-parties-brexit","status":"publish","type":"post","link":"https:\/\/alpha.pewresearch.org\/pewresearch-org\/global\/2026\/05\/28\/appendix-classifying-european-political-parties-brexit\/","title":{"rendered":"Appendix: Classifying European political parties"},"content":{"rendered":"\n

Classifying parties as populist<\/h3>\n\n\n\n

Although experts generally agree that populist political leaders or parties display high levels of anti-elitism, definitions of populism vary. We use three measures to classify parties as populist: anti-elite ratings from the 2024 Chapel Hill Expert Survey<\/a> (CHES), the 2023 Populism and Political Parties Expert Survey<\/a> (POPPA) and the 2023 PopuList<\/a>. We define a party as populist when at least two of these three measures classify it as such.<\/p>\n\n\n\n

CHES, which was conducted from October to December 2024, asked 609 political scientists specializing in political parties and European integration to evaluate the 2024 positions of 279 European political parties across all European Union member states, except for Luxembourg. The survey also gathered their views of parties in Iceland, Norway, Switzerland, Turkey and the United Kingdom. CHES results are regularly used by academics to classify parties with regard to their left-right ideological leanings, their key party platform positions and their degree of populism, among other things.<\/p>\n\n\n\n

We measure anti-elitism using an average of two variables in the CHES data. First, we used \u201cPEOPLE_VS_ELITE,\u201d which asked the experts to measure the parties with regard to their position on direct versus representative democracy, where 0 means the parties support elected officeholders making the most important decisions and 10 means the parties support \u201cthe people,\u201d not politicians, making the most important decisions. Second, we used \u201cANTIELITE_SALIENCE,\u201d which is a measure of the salience of anti-establishment and anti-elite rhetoric for that particular party, with 0 meaning the rhetoric is not at all salient and 10 meaning it is extremely salient. The average of these two measures is shown in the table below as \u201canti-elitism.\u201d We define parties that score 7.0 or more as populist.<\/p>\n\n\n\n

POPPA, which was fielded between January and May 2023, asked 324 experts to measure positions and attitudes of 312 political parties on key characteristics related to populism and political representation in 31 European countries. We used \u201cPOPULISM_MEAN,\u201d which is an average of five indicators:<\/p>\n\n\n\n