'The book is a pioneering attempt to see exactly what difference economic valuation of environmental effects would have made to six actual, on-going, development projects, if it had been done at the time of appraisal. It combines theoretical rigour with applied economic skills, presented with robust common sense.' - James Winpenny, Overseas Development Institute This book is a practical and readable guide to valuing the environment and the implications for public investment and policy, useful for students as well as professional economists, policy-makers, engineers, environmental and social planners. It describes how the environment can be valued and how these valuation concepts can be applied to investment decisions. The book provides first a general introduction to the key issues and concepts, considering the nature and magnitude of environmental problems, the cost-benefit method of evaluation and detailed methods for valuing the environment. It then analyses in detail six case-studies, based on actual or proposed major investment projects by the UK Overseas Development Administration or the World Bank. These include water quality in China, the supply of electricity in Bangladesh, slum improvements in India, mass transit in Nigeria, forest conservation in Kenya and soil quality in Bolivia. Thus the book is expected to be of special interest to professionals and students in developing countries, although much of the material has general application in developed as well as in developing countries.