Appendix B: Classifying political parties as populist

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 populist parties: anti-elite ratings from the 2019 Chapel Hill Expert Survey (CHES), Norris’ Global Party Survey and The PopuList. We define a party as populist when at least two of these three measures classify it as such.

CHES, which was conducted from February to May 2020, asked 421 political scientists specializing in political parties and European integration to evaluate the 2019 positions of 277 European political parties across all European Union member states. 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.

We measure anti-elitism using an average of two variables in the CHES data. First, we used “PEOPLE_VS_ELITE,” which asked the experts to measure the parties with regard to their position on direct vs. representative democracy, where 0 means that the parties support elected officeholders making the most important decisions and 10 means that “the people,” not politicians, should make the most important decisions. Second, we used “ANTIELITE_SALIENCE,” which is a measure of the salience of anti-establishment and anti-elite rhetoric for that particular party, with 0 meaning not at all salient and 10 meaning extremely salient. The average of these two measures is shown in the table below as “anti-elitism.” In all countries, we consider parties that score above a 7.0 as “populist.”

The Global Party Survey, which was conducted from November to December 2019, asked 1,861 experts on political parties, public opinion, elections and legislative behavior to evaluate the ideological values, issue position and populist rhetoric of parties in countries on which they are an expert, classifying a total of 1,051 parties in 163 countries. We used “TYPE_POPULISM,” which categorizes populist rhetoric by parties. We added only “strongly populist” parties using this measure. In Italy, experts were asked to categorize the Center-Right coalition instead of individual parties within the coalition. The coalition includes Lega and Forza Italia. For both parties, we have used the coalition rating of “strongly populist.”

The PopuList is an ongoing project to classify European political parties as populist, far right, far left and/or euroskeptic. The project specifically looks at parties that “obtained at least 2% of the vote in at least one national parliamentary election since 1998.” It is based on collaboration between academic experts and journalists. The PopuList classifies parties that emphasize the will of the people against the elite as populist.²

The Brexit Party in the UK is only classified as populist on one measure but is still included for analysis in the report. It is not included in the PopuList and does not meet our anti-elite CHES threshold of 7.0, but is considered a right-wing populist party by the Global Party Survey and other experts.

Classifying parties as left, right or center

We can further classify these traditional and populist parties into three groups: left, right and center. When classifying parties based on ideology, we relied on the variable “LRGEN” in the CHES dataset, which asked experts to rate the positions of each party in terms of its overall ideological stance, with 0 meaning extreme left, 5 meaning center and 10 meaning extreme right. We define left parties as those that score below 4.5 and right parties as those above 5.5. Center parties have ratings between 4.5 and 5.5.