I BEGAN THIS STUDY five years ago with the question of recycling. Several pieces of major legislation--including the National Environmental Policy Act and the Resource Recovery Act--had declared recycling to be a national goal. But how much recycling, which materials, what incentives? It soon became clear to me that questions of "optimal" recycling are tied to questions of optimal durability, exhaustion of the resource base, and the distributions of long-lived wastes generated by materials use: that is to say, recycling policy belongs in the broader context of materials policy.
In order to define the "optimal" balances between materials use and conservation and material waste generation and protection of the future from these wastes, some of which are extremely long-lived, it is necessary to know how to value the long-run costs of depletion and waste generated. At first this appears to be a straightforward problem to be handled by the discounting of future costs. But the problem becomes more complicated when one assumes, as I do in the latter part of this book, that the resource base is owned jointly across generations (here the resource base refers not only to the positively valued resources "in the ground" but also to the negatively valued material wastes generated by materials use). Once the resource base is recognized as belonging to all generations, it becomes clear that we must ask what is a fair or equitable intergenerational use of the resource base. As I will try to illustrate, this question goes beyond choosing a discount rate and using it.
Discussion of the fair use, intertemporally, of the resource base is not a new discussion. It is the principal focus of much of the conservationist literature. In the economics literature on natural resources, however, the