What Do We Measure When We Measure Affective Polarization across Countries?

Abstract Measures of affective polarization—that is, dislike and hostility across party lines—have been developed and validated in the context of America’s two-party system. Yet increasingly, affective polarization is examined comparatively. We address this issue by introducing a novel dataset that measures aspects of partisan affect in 10 countries with diverse party systems. We detect associations between partisan affect toward out-parties versus affect toward out-parties’ supporters, but their strength varies across countries. We discuss measurement reasons for this variation and consider the implications of our findings for the emerging comparative affective polarization literature.