Is there a role for ecology in a cost–benefit society? As a prelude to a collection of papers arising from a conference on this theme held at Roskilde University in June 2004, this paper summarizes divergent approaches to public policy decision making. Whether based on strict cost–benefit analysis or wide-ranging discussion, we make the point that decisions need to be informed by an understanding of the causes behind environmental problems and their consequences, through impaired ecosystem services, on the economy. Taking this forward will require forums that bring ecologists, economists, and regulators into active and constructive dialogue.