Economic analysis for policy appraisal is generally interested in answering two questions, "is a given policy objective worth achieving" and if so, "has the policy objective been achieved in the most cost-effective way?" While the first question is addressed in a cost-benefit analysis (CBA), the second question can be answered with the help of a cost-effective analysis (CEA). The authors of this book chapter focus on ex-post CEA and reveal problems, challenges and opportunities of CEA at the European level.

How can the effectiveness of environmental policies be assessed in retrospect? Have the stated targets of environmental policies been achieved, and if so, was it because of the policies or because of other factors? Have targets been achieved at proportionate costs, or could there have been cheaper options of reaching them? These and other questions on ex-post policy evaluation were discussed at an expert workshop convened by the European Environment Agency and the Environment Agencies of Denmark, the Netherlands and the UK. Benjamin Görlach gave an introduction to cost-effectiveness analysis as an evaluation tool, and presented experiences with ex-post cost-effectiveness analyses of environmental policies in Europe.

Along with the emphasis on better regulation and lean governance in the European Union and its Member States, there has been renewed interest in policy evaluation and impact assessment. One of the main criteria in this context is cost-effectiveness, which demonstrates that environmental objectives have been achieved – or will be achieved – at least cost. At the EASY-ECO conference "Impact Assessment for a New Europe and Beyond", Benjamin Görlach was invited to present some insights on state of the art ex-post assessments of the cost-effectiveness of environmental policies.

The European Environmental Agency (EEA) wishes to improve its methodological framework in the area of cost-effectiveness assessments and environmental-economic analysis. Ecologic supports the EEA in this task by creating an inventory of applied ex-post evaluation studies with a focus on methodologies, guidelines, legal requirements and good practice examples from the EU Member States. <p>Ecologic in co-operation with eftec and IVM carries out a review of experiences with cost-effectiveness analyzes, methods and outcomes in the environmental arena. The project's objectives are:</p>&#13; <ul></ul>