Resource productivity is the quantity of good or service (outcome) that is obtained through the expenditure of unit resource.
For example, when applied to crop irrigation it is the yield of crop obtained through use of a given volume of irrigation water, the “crop per drop”, which could also be expressed as monetary return from product per use of unit irrigation water.
Their strength is that they can be used as a metric for both economic and environmental cost.
Scientific and political debates on resource productivity are regularly held at, among others, the World Resources Forum conferences.
This article about energy economics is a stub.