Populism studies have rapidly burgeoned but nevertheless systematic cross-national evidence about this phenomenon has lagged far behind. How can populism be measured in ways which are consistent, valid, and reliable? To address this issue, Part I outlines the minimalist concept of populism used in the study. Part II summarizes the pros and cons of previous attempts at gauging and classifying party ideological values and issue positions in general, as well as recent studies seeking to classify populists as a distinct party family. Part III describes the research design employed to construct the Global Party Survey, replicating the methods of previous expert surveys but expanding coverage worldwide and including innovative measures of populist rhetoric. The new dataset, drawing upon estimates from 1,861 experts, covers 1,043 political parties in 163 countries around the globe (see www.GlobalPartySurvey.org). Part IV presents key results and a series of robustness tests confirming that the new estimates of ideological values and populist parties are consistently correlated with previous measures. The conclusion in Part V summarizes the results and considers the potential uses of the dataset for understanding populism as a global phenomenon.
Norris, Pippa. "Measuring Populism Worldwide." HKS Faculty Research Working Paper Series RWP20-002, February 2020.