Each unit of labor, for instance, is depleted immediately, as are certain kinds of capital goods, such as gasoline. On the other hand, capital goods such as tools may be much more durable; a hammer may provide services many thousands of times. Land has both depletable and non-depletable features. Land resources such as trees may be depleted, unless they are replenished by a process such as planting; such depletion decreases the market value of the land containing those resources. As a site for productive activity, on the other hand, land may be perfectly durable, at least for purposes of ordinary analyses of human action.

The monetary value of any factor cannot exceed its marginal (money) value to producers. For a depletable factor such as labor, that value is simply its contribution to the consumer product, after subtracting interest for the period of production. This value is its Discounted Marginal Value Product, which is conventionally abbreviated DMVP.