ABSTRACT
This chapter explores in a rather preliminary way the problems that appear to arise naturally when the existence of exhaustible resources is incorporated into the study of intertemporal plans. It considers the problems that arise from the implications that a finite earth has for intertemporal planning. The chapter describes a constant level of population through time. It analyses a world in which the objective of zero population growth has been acccepted and achieved. The chapter demonstrates that the elasticity of substitution between reproducible inputs and exhaustible resources plays an important and a rather direct role in the properties of an optimal plan. It presents a model incorporating technical progress under uncertainty. A more important source of uncertainty seems to be the exact timing of the availability of the substitute. The chapter shows that the random variable is uninfluenced by policy; that is, that the acquisition of knowledge is costless.
