Populist parties in European Parliament elections: A new dataset on left, right and valence populism from 1979 to 2019

Abstract Despite the increasing interest in populism, there is a lack of comparative and longterm evidence on the electoral performance of populist parties. We address this gap by using a novel dataset covering 92 populist parties in the European Parliament elections from 1979 to 2019. Specifically, we provide aggregate data on the electoral performance of all populist parties as well as the three ideational varieties of populism, i.e. right-wing, left-wing and valence populist parties. We show that there is significant variation both across countries as well as between the ideational varieties of populism. Most notably, while the success of left-wing and valence populists is concentrated in specific areas, right-wing populist parties have consolidated as key players in the vast majority of EU countries.