[ppt]chapter 4 - university of pittsburghstanko/busecon/production.ppt · web viewproduction...
TRANSCRIPT
Production Analysis• Production Function Q = f(K,L)
• Describes available technology and feasible means of converting inputs into maximum level of output, assuming efficient utilization of inputs:• ensure firm operates on production function (incentives for workers to put max
effort)
• use cost minimizing input mix
• Short-Run vs. Long-Run Decisions
• Fixed vs. Variable Inputs
Total Product
• Cobb-Douglas Production Function
• Example: Q = f(K,L) = K.5 L.5
• K is fixed at 16 units.
• Short run production function:
Q = (16).5 L.5 = 4 L.5
• Production when 100 units of labor are used?
Q = 4 (100).5 = 4(10) = 40 units
Marginal Product of Labor
• Continuous case: MPL = dQ/dL
• Discrete case: arc MPL = Q/L
• Measures the output produced by the last worker.
• Slope of the production function
Average Product of Labor
• APL = Q/L
• Measures the output of an “average” worker.
• Slope of the line from origin onto the production function
Law of Diminishing Returns (MPs)TP increases at an increasing rate (MP > 0 and ) until inflection , continues to increase at a diminishing rate (MP > 0 but ) until max and then decreases (MP < 0).
0
5
10
15
20
25
0 2 4 6 8 10 12
Input L
Tota
l Pro
duct
-4
-3
-2
-1
0
1
2
3
4
0 2 4 6 8 10 12
Three significant points are: Max MPL (TP inflects) Max APL = MPL
MPL = 0 (Max TP)
A line from the origin is tangent to Total Product curve at the maximum average product.
IncreasingMP
DiminishingMP
NegativeMP
Isoquant
• The combinations of inputs (K, L) that yield the producer the same level of output.
• The shape of an isoquant reflects the ease with which a producer can substitute among inputs while maintaining the same level of output.
• Slope or Marginal Rate of Technical Substitution can be derived using total differential of Q=f(K,L) set equal to zero (no change in Q along an isoquant)
K
L
MPMP
KQ
LQ
LKL
LQK
KQ
0
Cobb-Douglas Production Function• Q = KaLb
• Inputs are not perfectly substitutable (slope changes along the isoquant)
• Diminishing MRTS: slope becomes flatter
• Most production processes have isoquants of this shape
• Output requires both inputs
Q1
Q2
Q3K
-K1
||
-K2
L1 < L2 L
Increasing Output
KL
aa
LKabfor
1
,1
Linear Production Function
• Q = aK + bL
• Capital and labor are perfect substitutes (slope of isoquant is constant)y = ax + bK = Q/a - (b/a)L
• Output can be produced using only one input Q3Q2Q1
Increasing Output
L
K
Leontief Production Function
• Q = min{aK, bL}
• Capital and labor are perfect complements and cannot be substituted (no MRTS <=> no slope)
• Capital and labor are used in fixed-proportions
• Both inputs needed to produce output
Q3
Q2
Q1
K
Increasing Output
Isocost• The combinations of inputs
that cost the same amount of moneyC = K*PK + L*PL
• For given input prices, isocosts farther from the origin are associated with higher costs.
• Changes in input prices change the slope (Market Rate of Substitution) of the isocost lineK = C/PK - (PL/PK)L
K
LC1C0
L
KNew Isocost for a decrease in the wage (labor price).
New Isocost for an increase in thebudget (total cost).
Long Run Cost Minimization
K
K
L
L
PMP
PMP
Q
L
K -PL/PK < -MPL/MPK
MPK/PK< MPL/PL
-PL/PK > -MPL/MPK
MPK/PK> MPL/PL
Point of CostMinimization
-PL/PK = -MPL/MPK
MPK/PK= MPL/PL
Min cost where isocost is tangent to isoquant (slopes are the same)
Expressed differently: MP (benefit) per dollar spent (cost) must be equal for all inputs
KLK
L
K
LKL MRTS
MPMP
PP
MRS