Time discounting in Harold Hotelling's approach to natural resource economics: the unsolved ethical question

The paper focuses on Harold Hotelling's approach to time discounting in the context of the intertemporal allocation of exhaustible natural resources. In 1931, Hotelling introduces a positive discount rate when dealing with the "social value" or "total utility" derived from a resource. His position was in contrast with early economic literature on conservation, as well as with the point of view of Frank Ramsey, according to whom time discounting expressed an unjustified preference for the welfare of present generations over that of future ones. Hence, it has been argued that Hotelling dismissed ethical concerns. Using archival material, we find that, for Hotelling, economic questions should not be restricted to issues of economic efficiency; that his choice to discount utility – which he considered as analogous to a concrete benefit – at the interest rate is compatible with Ramsey's position; and, more broadly, that this choice does not preclude an ethical position on the desirable distribution of exhaustible resources through time. To Hotelling, ethics is implemented by politics, through fiscal corrections of the interest rate. Revisiting Hotelling on the articulation between ethics, allocative efficiency, and policies allows us to rethink the way we do that in current models using time discounting.