IOs face strong pressures for change, while operating under a fragmented institutional environment. In their efforts to adapt and keep their focal authority, they enter into collaborative arrangements with various non-state actors. These ‘organized’ arrangements and resulting governance structures influence the organizational adaptation of an IO (the development of adaptive capabilities). Drawing on organization theory and on rational-choice institutionalism, I investigate how IOs adapt to a complex institutional environment. I argue that governance structures (formality of contracts, decision-making rules, monitoring mechanisms and financial interdependence) ruling over an organizational field condition the exchange of information and IO’s adaptation. By exploring two case studies with distinct inter-organizational governance structures within the World Health Organization’s inter-organizational field of malaria, I explain how the adaption process of an IO unfolds under competitive, or hierarchical environments. I specify a mechanism of adaptation, whereby exchange of information and competences from external partners through specific governance arrangements, can facilitate adaptation. A cross-case comparative analysis of two most differentiated cases, followed by a within-case process tracing, are combined to refine the causal pathway from specific governance structures to exchange of competences to adaptation.
