Discussions of policy transfer have primarily focused on official actors and networks. The non-governmental mode of policy transfer via foundations, think tanks and non-governmental organizations is a relatively neglected dimension. Accordingly, this paper addresses the role of think tanks in promoting the spread of policy ideas about privatization. The importance of think tanks to policy transfer is their ability to diffuse ideas by (1) acting as a clearing-house for information; (2) their involvement in the advocacy of ideas; (3) their involvement in domestic and transnational policy networks; and (4) their intellectual and scholarly base providing expertise on specialized policy issues. Concepts from comparative public policy and international relations such as "social learning" and "epistemic communities" are used to outline the way think tanks advocate innovative policy ideas. However, not only have think tanks been effective in promoting the transfer of policy ideas, the international spread of think tanks also exhibits organizational transfer.