The production function and The Marginal Product of Labor The production function illustrates the relationship between the quantity of inputs used and the quantity of output of a good H arc Inc items and derived items copyright o 2001 by Harcourt, IncHarcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc. The Production Function and The Marginal Product of Labor The production function illustrates the relationship between the quantity of inputs used and the quantity of output of a good