Are rules for the world governed by international organizations'' bureaucracies or private authority? Certainly both. This paper questions the utility of a distinction between international bureaucracies and transnational private authority, and points to how actors responsible for governing the world economy move between public and private roles through linked professional ecologies. We borrow from Andrew Abbott’s work on ‘linked ecologies’, in which actors within different professional ecologies form coalitions to create alliance strategies in which they can propagate the relevance of their ideas and skills. If successful, an alliance between ecologies can take control of a policy ‘location’ – how a policy problem should be legitimately understood. To test the relevance of linked ecologies arguments we examine how the Basel Committee and organizations such as the Group of Thirty and the Joint International Monetary Fund-World Bank Financial Sector Assessment Program (FSAP) have attempted to control the policy location for financial stability reform within the world economy pre and post-crisis. We draw upon interviews with participants from these institutions to assess the extent to which actors were able to link ecologies and successfully gain control of the policy location for financial stability reform.