Crises and public support for European integration: a conjoint experiment

Crises are often treated as engines of European integration, although the public-opinion mechanism behind crisis-led integration remains underspecified. This article argues that support for EU crisis powers depends on the configuration of the crisis: its symmetry, intensity, field of impact, direct national exposure, and attribution of responsibility. The argument is tested through a crisis-profile conjoint experiment fielded in France, Germany, Italy, Poland, Spain, and the United Kingdom between 20 April and 1 May 2025. Respondents evaluated crisis profiles and indicated whether the EU should receive fewer powers, no change in powers, or more powers to address the crisis. The results indicate that military crises, high-intensity crises, symmetric crises, and crises directly affecting the respondent's country create more favourable public-opinion conditions for EU competence expansion. Fiscal and economic crises generate less support than military crises and natural-disaster crises. Attribution of responsibility mainly affects opposition to integration: when EU policies are not blamed for the crisis, respondents become less likely to prefer fewer EU powers. These findings identify demand-side conditions under which stylised crisis descriptions make European action more acceptable as protection against a common shock.