DEVELOPMENT, THE ENVIRONMENT, AND THE SOCIAL RATE OF DISCOUNT

This article examines the role of the discount rate in makingdecisions that will have significant implications for the environment.The authors begin by providing a rationale for discounting ingeneral and by describing the main factors that determine thediscount rate. These factors—the private and social ratesof time preference, the opportunity cost of capital, risk anduncertainty, and the interests of future generations—allhave an environmental dimension. The article goes on to examinethat dimension and to explore the connections between the choiceof the discount rate and environmental concerns, such as excessiveexploitation of natural resources, inadequate investment inconservation, and insufficient attention to the irreversibleloss of certain environmental resources. The authors conclude that, in general, environmental concernsare not best addressed by lowering the discount rate—anaction that might have both benefits and costs for the environment.A more promising course would be to incorporate a criterionof sustainability into certain aspects of decisionmaking. Howsuch a criterion could be made operational is touched upon butnot developed in this article.