In: Economics
Consider the production function ? = ? 1 3? 2 3. Let r and w denote the prices of K (capital) and L (labor). Suppose ?̅ = 27 (fixed) and L is variable.
a. Write down the expression for the short-run production function.
b. Compute the marginal product of labor (??? ) and the average product of labor (??? ). Is the ??? increasing or decreasing? Is ??? >, <, or = ????
c. Find expressions for fixed cost [F], variable cost [VC(q)], average cost [AC(q)] and marginal cost [MC(q)].
d. Find the production efficient level of output (q * ) where unit costs (AC) are cheapest (minimized), your answer will depend on w and r.
e. If a $15 specific tax per unit is imposed, what are the new cost functions (FC, VC, AC and MC)?
q = L1/3K2/3
(a)
In short run, K = 27. Substituting in production function,
q = L1/3(27)2/3
q = 9 x L1/3 [Short run production function]
(b)
MPL = dq/dL = [9 x (1/3)] / L2/3 = 3 / L2/3
APL = q/L = 9 / L2/3
With increase in L, (L2/3) increases, so MPL is decreasing.
Since 3 < 9,
(3 / L2/3) < (9 / L2/3).
In other words,
MPL < APL.
(c)
Short run production function: q = 9L1/3
L1/3 = q/9
Cubing:
L = q3/729
Fixed cost (FC) = Total capital Cost = rK = 27r
VC(q) = Total labor Cost = wL = w x (q3/729)
TC(q) = FC + VC(q) = 27r + w x (q3/729)
AC(q) = TC(q)/q = (27r/q) + (wq2/729)
MC(q) = dTC(q)/dq = (wq2/81)
(d)
Average cost is minimized when dAC(q)/dq = 0
dAC(q)/dq = -(27r/q2) + (2wq/729) = 0
27r/q2 = 2wq/729
q3 = (729 x 27r)/2w = 9,841.5 x (r/w)
q = 21.43 x (r/w)1/3
(e)
A specific tax is a form of fixed cost, imposition of which will have no change in VC(q) and MC(q)..
New FC = 27r + 15
New TC(q) = 27r + 15 + (wq3/729)
New AC(q) = TC(q)/q = (27r/q) + (15/q) + (wq2/729)