Does legitimacy drive international institutional change? This article examines three causal mechanisms by which variation in legitimacy induces regional parliamentarization. Using survival analysis on a novel dataset of thirty-six regional organizations from 1950-2010, the authors find empowerment of supranational secretariats, proximity to the European Union, and neighborhood parliamentarization increase adoption rates. These results reveal that legitimacy judgments stem from cognitive referents—a previously overlooked source of institutional change.
The findings highlight a key mechanism behind these changes: cognitive emulation. Illustrating this with the case study of Southeast Asian Nations' parliamentarization process shows how member states mimic successful models based on perceived legitimacy.
