Legitimacy in Time: Institutional Design, Legitimacy Drift and Decoupling at the UN Security Council

Representation is often central to institutional legitimacy. This article offers a theory of the legitimacy of international organizations in time. Conceiving of legitimacy as a feature of institutional design, it develops the concept ‘legitimacy drift’ to identify the processes by which institutional legitimacy can gradually diminish over time. Three sources of legitimacy drift are identified: changes in an organization’s relevant public (audience shift), changes in perceptions of whether an organization meets pre-existing standards of legitimacy (legitimacy erosion), and shifts in the standards of legitimacy themselves (shifting standards). Responses to legitimacy drift include re-legitimation through institutional reform, and the emergence of organizational and rhetorical decoupling. It is theorised that decoupling is especially likely where reform is blocked due to factors such vested interests and veto players. The theory is elaborated on the exemplary case of the UN Security Council, shedding new light on the origins and effects of its current legitimacy deficit. The analysis shows how interpretations of representative legitimacy have changed, from a focus on the representation of power to one of the representation of the UN membership. A conclusion calls for bridging rival institutionalist theories to better understand IO legitimacy in time.