Presenting a cross nationally validated populist attitudes scale

Research into the causes of populism has taken a turn to the individual level in recent years. Some attempts have been made at trying to measure populism as an attitude. These have often been confined to one country, and the scales used have changed in each study. This paper develops a scale that measures separately each dimension of the concept of populism, and psychometrically validate it in four countries: Croatia, Greece, Spain, and the United States. From an original 136 items, we use Exploratory Factor Analysis and the align- ment method of testing measurement invariance to reduce this number to 30 invariant ones, spread across four relevant dimensions: people-centrism, anti- elitism, Manichaean outlook of politics, and an anything-goes attitude towards political opponents. Based on them, we end with a suggestion of a 16-items scale with the best performing questions.