I review the literature on natural resource scarcity indicators. Scarcity indicators can be classified by what is being measured: value of the resource stock or value of extracted resource commodities; who's value is considered: social vs. private scarcity; and by the mode of valuation considered: exchange value and use value. Prices and rents are common measures of exchange value or indicators of 'exchange scarcity' and unit costs can be seen as use value indicators or indicators of 'use scarcity'. The major aim of this paper is to demonstrate the links between productivity indicators such as unit costs and the classical concept of use value. The two classes of indicator relate to John Commons' discussions of scarcity and efficiency, and a marginal vs. a non-marginal approach to value and scarcity. The classical use value concept also has wider relevance for issues of valuation in energy, resource, and environmental policy.