Populism studies have rapidly burgeoned but systematic global empirical evidence about this phenomenon has lagged behind. How can party values be measured in consistent, valid, and reliable ways, facilitating identification of varieties of populism in countries around the world? To address this issue, part I outlines the conceptual framework. Part II describes the research design. The Global Party Survey (GPS) replicates previous expert surveys, expands coverage worldwide, and incorporates innovative scaled measures of populism. It draws upon estimates from 1861 experts and covers 1043 political parties in 163 countries (see www.GlobalPartySurvey.org). Part III summarizes some key cross-national results. Part IV presents robustness tests which confirm that the new GPS estimates of ideological values and populist parties are consistently correlated with several previous measures. The conclusion in part V summarizes the main findings and considers the potential uses of the data set for understanding populism as a global phenomenon.
Norris, Pippa. "Measuring Populism Worldwide." Party Politics 26.6 (November 2020): 697–717.