The perception that an income today is worth more than the same income tomorrow underlies the process of discounting future values, the almost universal basis of resource evaluation and of public and private investment decision-making. In this text, Colin Price argues that the premises on which discounting is based are mistaken, the logic underlying it misconceived and the case for applying it in practice untenable. The early chapters review the traditional arguments for discounting - based on return on investment and human preference for immediate consumption - and finds them fatally flawed. The central part of the book examines in detail the underlying causes for value changes over time, and the effectiveness of conventional discounting in representing these changes. It covers physical, technological, psychological, financial, ethical and political factors. The final chapters suggest how resources may be valued and investments selected for the future benefit of this generation, and for that of future generations. This is, in sum, a contribution to a central debate in economics and public accounting, illustrated with a wide range of examples and cases. It raises issues which need to be addressed if economics is to claim ethical legitimation, and if resources are to be managed sustainably. It is fully referenced and indexed, and contains diagrams. The text should be suitable for students of environmental economics, resource economics and environmental science.