This two-volume set collects key essays examining economic theory, methods, and issues salient to agri-environmental policy in the US and in Europe, as well as in other countries. The topics under discussion are arranged thematically and include theoretical, numerical and empirical works; all are grounded in policy and economics. The introduction to these volumes reviews the evolution of agri-environmental policies, with an important focus on the history of US policy and European agri-environmental policy. A key feature within this is the importance of the Environmental Protection Agency (EPA) in the US, particularly its move towards more 'market-based incentives' from the 1980s onwards. Within the European context, the effects of the CAP (Common Agricultural Policy) on agri-environmental programmes and schemes within the member states, are discussed. Significantly, the essays republished here have provided the knowledge base that has influenced further applied work, creating an influential impact on policy development.