Joe owns a tree cutting company. His firm uses tree cutters(L) and equipment (K) in
cutting trees. Suppose that the cost of hiring a tree cutter(w) is $10 an hour and the cost of using
equipment (r) is $30 an hour. We will consider how much K andL Joe should use to cut 75 (i.e., Q
= 75) trees. (Make sure that you specify intercepts, optimalamounts of K and L and isoquants
clearly on graphs.)
1.)
Suppose that Joe’s production function is Q = 15K + (2.5)L.Marginal product of capital
MPK = 15, and marginal product of labor MPL = 2.5. What arethe values of the cost-minimization
bundle of K and L? Draw his isoquant and isocost curves andidentify the firm’s cost minimizing
combination of K and L to represent the cost minimizationsolution on the graph.
2.)
Suppose that Joe’s production function is now Q = KL. Joe’smarginal product of capital
and labor are MPK = L and MPL= K, respectively. What are thevalues of the cost-minimization
bundle of K and L? Draw his isoquant and isocost curves andidentify the firm’s cost minimizing
combination of K and L to represent the cost minimizationsolution on the graph.
3.)
Suppose that the wage rate increases to $15 per hour. For eachof the production functions
identified in parts (a) and (b), identify what will happengenerally to the optimal amounts of K and
L. (Just identify whether K will increase, decrease or staythe same and whether L will increase,
decrease or stay the same. You do not have to solve for theexact changes.) Justify your answers
using graphs.