Putting a price tag on the environment is controversial. The aim of this book is to discuss some of the ethical and political issues arising in the context of applied cost-benefit analysis and environmental valuation - and to do so using economic analysis, but in a language accessible to non-specialists. In particular, the author emphasizes the fundamental, but surprisingly often poorly understood distinction between normative and positive analysis, and the implications of this distinction for practical use of cost-benefit analyses. Most books in cost-benefit analysis assume, implicitly or explicitly, that the purpose of a project assessment is to rank projects according to their net contribution to social welfare. However, the starting point of this book is different. Here, the purpose of a project assessment is to enable participants in a democratic decision-making process to make their own well-founded rankings of projects, according to their own normative views. Since ethical and political views differ, the analysis should be useful as factual background for any reasonable social welfare judgement.This book provides a systematic and easily accessible discussion of such issues, based on economic theory, but with a strong emphasis on applicability. It is aimed at those - economists and non-economists alike - who use or are faced with cost-benefit analysis and environmental valuation in their work: politicians, employees of ministries and regulatory agencies, students, journalists, consultants and researchers.