Who exercises political authority in international politics? Besides autonomy and independence of international actors, in recent years the concept of delegation has grown increasingly popular for explaining the authority of international organisations. This paper argues, however, that the concept of delegation suffers from both empirical and theoretical shortcomings. Empirically, the mere existence of an international secretariat often is sufficient to scholars for identifying some instance of delegation of authority, independent of what tasks are delegated to an international organisation. Conceptually, delegation describes merely one possible relationship between those who have political authority, on the one hand, and those who exercise authority, on the other hand.

Moving beyond the conceptualisation of delegation for measuring the authority of international organisations, this paper proposes international actorness a framework for understanding and conceptualising the authority of international actors, describing a rather diffuse boundary between the actorness of international organisations and groups of states. Analysing the relationship between authority and actor as well as the type of actors, this paper identifies four ways of exercising authority in international politics: The sovereign, collective, delegated and transferred exercise of authority. These four types of international actorness appear across different policy areas and do not necessarily correspond to the mere absence or existence of an IO. This paper develops the concept of international actorness as well as the respective typology and presents empirical findings on the four types of actorness.