ABSTRACT
In your introductory microeconomics course the marginal product ofL(MPL)was probably defined as the increase in TPL caused by a one-unit increment in L, assuming K to be fixed at some given level. A more precise definition, however, is that MPL is the rate of change of TPL with respect to L. For any given value of L this is the slope of the TPL function. (Refer back to Section 8.3 if you do not understand why.) Thus the MPL schedule in Figure 10.1 is at its maximum when the TPL schedule is at its steepest, at M, and is zero when TPL is at its maximum, at N.
