Suppose that a firm’s production function is given by =K0.33L0.67 , where PK=0.33K−0.67L0.67 , and PL=0.67K0.33L−0.33 . a. As L increases, what happens to the marginal product of labor? b. As K increases, what happens to the marginal product of labor? c. Why would MPL change as K changes? Labor and capital are substitutes. Technology makes capital more valuable, so firms use more capital and less labor. Labor becomes more productive when capital increases. Capital crowds out labor. d. As capital increases, MPK , and as labor increases, MPK .