Suggestions on the paper from Antoine Dechezlepretre, Rob Youngman, Simon Buckle (all from the OECD Environment Directorate) and Hans Lundgren (OECD Development Co-operation Directorate) are also appreciated. The author would also like to thank delegates of the OECD Working Party on Biodiversity, Water and Ecosystems for helpful comments on earlier drafts of this paper. The author is responsible for any remaining omissions or errors.