A widening authority–legitimacy gap in EU regulatory governance? An experimental study of the European Medicines Agency’s legitimacy in health security regulation

Agencification in the EU stretches the confines of the European regulatory state to the maximum by extending to policy domains that were formerly the exclusive terrain of national institutions. Although the challenge to legitimize EU-level agencies is widely acknowledged, scant empirical research has been done on the conditions under which EU-level epistemic authority prevails or fails. To fill this gap, we examine whether EU agencies are perceived as more legitimate when the scientific nature of their regulatory outputs is made explicit and whether they start facing grave legitimacy challenges when national-level stakeholders signal disapproval with their scientific recommendations. We draw on a survey experiment with Dutch local politicians to study their legitimacy perceptions about the European Medicines Agency (EMA) and its mandate to authorize vaccines in view of cross-border health security risks. Our data suggest that the EMA is regarded as a highly legitimate agency and that disapproval by national-level politicians and citizens does not undermine its epistemic authority in the eyes of local decision-makers. This study contributes to the scholarship on non-majoritarian institutions’ legitimation imperatives by introducing novel research avenues and analytical tools to continue rigorous empirical testing of the well-established theoretical and normative claims.