Actualisation en forêt: Pour quelles raisons et à quel taux?

Abstract

Financial evaluation of forest projects based on cost-benefit analysis uses a calculation of the Net Present Value for all revenues and costs throughout the project's life cycle. This paper recaps the justification for discounting financial flows (revenues and costs) and the difficulties that arise in the case of long term projects involving environmental goods and services. In Part 1, the microeconomic foundation for the net present value method is recalled: pure preference for the present, wealth effect connected with growth and the precautionary effect arising from risk aversion. Part 2 deals with the particular case of environmental, non-market goods and services and considers trends in their relative prices. Part 3 describes the possible justification for diminishing the discount rate over time, particularly for very long term projects, together with common assumptions made about the discount rate in forestry economics.