Popular Legitimacy

JOP 88/2 pp. 732-745 2026-04-01 Original Effects of Popular Legitimacy on International Organizations: An Elite Survey Experiment Thomas Sommerer, Jonas Tallberg Abstract Whether or not popular legitimacy matters for international organizations (IOs) is a topic of extensive assumption but little rigorous research. A key obstacle has been the methodological difficulties of establishing legitimacy’s effect using observational data. This article offers the first experimental study of the effects of popular legitimacy on IOs. Theoretically, we propose that popular legitimacy affects IOs through the mechanism of government responsiveness to public opinion. Empirically, we test this expectation by presenting elected politicians in Sweden with a scenario of proposed reforms to the World Health Organization (WHO) and randomized information about the organization’s degree of popular legitimacy. The results show that higher levels of popular legitimacy made politicians more willing to confer additional authority and resources on the IO. The effects were particularly large among politicians with positive pretreatment attitudes toward the WHO and leftist ideological orientations. These findings suggest that popular legitimacy matters by affecting national decision-makers’ willingness to empower IOs.