The Popu-List is an essential tool for identifying populist parties, but it does not provide
a comprehensive analysis of their ideological varieties. This article introduces the
PopulisTree, a taxonomy that systematically classifies populist actors into five main
types—populist right, left, agrarian, regionalist, and valence—as well as more specific
sub-types, including the populist radical right. The taxonomy’s utility is demonstrated
through its application to the 2024 European Parliament (EP) elections and the development
of the PopulisTreeEU dataset, which provides information on the ideology,
votes, seats, and EP political groups of populist parties in EP elections since 1979.
Furthermore, in its dedicated website, the PopulisTree taxonomy is applied to all the
parties included in the Popu-List, enabling its adoption for the study of national
elections.
