In: Economics
Consider the same firm from above but this time assume the firm is operating in the long-run, i.e. it can vary K as well. As before, the firm’s production function is q = 4K0.5L 0.5 and the wage rate is w = $8 and the rental rate of capital is r = $2.
a) What is the optimal long-run relationship between K and L?
b) If the firm is producing 24 units, how much labor will it employ?
c) How much capital will it employ?
d) What is the (long-run) cost of producing 24 units?
e) If the total cost function is linear then, using your answer from (d), what is the slope of this line and the long-run total cost function?
f) Comparing your answers to 3(f) and 2(c), why is the average total cost of producing 8 units the same in the short- and long-run? Why is the long-run ATC of producing a different quantity smaller than the short run ATC?
Thank you for your help, I appreciate it!
a) Optimal long-run relationship between K and L is determined
at the point where MRTS = w/r
So, MRTS = MPL/MPK
MPL =
MPK =
So, MRTS =
So, K/L = w/r = 8/2 = 4
So, K = 4L
b) q = 4K0.5L 0.5 = 24
So, q = 4(4L)0.5L 0.5 = 24
So, 4*2L0.5+0.5 = 24
So, 8L = 24
So, L = 24/8 = 3
L = 3
c) K = 4L = 4(3) = 12
So, K = 12
d) Cost = wL + rK = 8(3) + 2(12) = 24 + 24 = 48
e) Slope = -dK/dL = -(dC/dL)/(dC/dK) = -w/r = -8/2 = -4
f) Parts 3f and 2c are not given. So this can not be answered.