Mineral Depletion and the Rules of Resource Dynamics

Conditions of exploitation of natural resources under certainty and uncertainty in some canonical natural resource problems are unified as r-percent rules by which the sum of all sources of gain from refraining from an irreversible action is compared to the interest rate. Action is initiated once the gain from action equals the gain from inaction. Morris Adelman’s insights, succinctly presented his 1990 paper on mineral depletion, are highlighted as implicitly recognizing, and even being grounded by, these timing rules.