The Costs of Production Chapter 8 McGraw-Hill/Irwin Copyright © 2009 by The McGraw-Hill Companies, Inc. All rights reserved.
Dec 28, 2015
The Costs ofProduction
Chapter 8
McGraw-Hill/Irwin Copyright © 2009 by The McGraw-Hill Companies, Inc. All rights reserved.
Chapter Objectives
• Explicit and implicit costs• Law of diminishing returns• Fixed and variable costs• Total, average, and marginal
costs• The firm’s size in the long run
8-2
Economic Costs
• Equal to opportunity costs• Explicit + implicit costs• Explicit costs
–Monetary payments
• Implicit costs–Value of next best use–Self-owned resources–Self-employed resources
8-3
Profit
• Accounting profit–Total revenue less explicit cost
• Normal profit–Equal to implicit cost
• Economic or pure profit–Total revenue less economic cost
8-4
Profits Compared
EconomicProfit
AccountingCosts (Explicit
Costs Only)
AccountingProfit
ExplicitCosts
Implicit Costs(Including a
Normal Profit)
Eco
no
mic
(Op
po
rtu
nit
y)C
ost
s
To
tal
Rev
enu
e
Economic Accounting
8-5
Short and Long Run
• The short run–Fixed plant capacity
–Variable intensity of plant use
–Variable output
• The long run –Variable plant capacity
–Firms enter and exit
8-6
Production Relationships
• Total product (TP)• Marginal product (MP)
• Average product (AP)
Average Product Total Product
Units of Labor=
Marginal ProductChange in Total Product
Change in Labor Input=
8-7
Law of Diminishing Returns
• Fixed technology
• Add variable resource to fixed resource
• Marginal product will decline–Beyond some point
• Rationale
8-8
IncreasingMarginalReturns
Law of Diminishing Returns
(1)Units of the
Variable Resource(Labor)
(2)Total Product
(TP)
(3)Marginal Product
(MP),Change in (2)/Change in (1)
(3)AverageProduct
(AP),(2)/(1)
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01025456070757570
1015201510
50
-5
-10.0012.5015.0015.0014.0012.5010.71 8.75
]]]]]]]]
DiminishingMarginalReturns
NegativeMarginalReturns
8-9
0
10
20
30
To
tal P
rod
uct
, TP
1 2 3 4 5 6 7 8 9
20
10
Mar
gin
al P
rod
uct
, MP
1 2 3 4 5 6 7 8 9
TP
MP
AP
IncreasingMarginalReturns
DiminishingMarginalReturns
NegativeMarginalReturns
Law of Diminishing Returns
8-10
Short-Run Production Costs
• Fixed Costs–Do not vary with output
• Variable Costs–Materials, most labor
• Total Cost–TC = TFC + TVC
8-11
Per-Unit Production Costs
• Average fixed cost AFC = TFC/Q
• Average variable costAVC = TVC/Q
• Average total cost ATC = TC/Q = TFC/Q + TVC/QATC = AFC+AVC
• Marginal costMC = change in TC/change in Q
8-12
Short-Run Production Costs
Co
sts
1 2 3 4 5 6 7 8 9 100 Q
100
200
300
400
500
600
700
800
900
1000
$1100
TFC
TC
TVC
TotalCost
VariableCost
FixedCost
8-13
Short-Run Production Costs
Co
sts
1 2 3 4 5 6 7 8 9 100 Q
50
100
150
$200
AFC
MC
ATCAVC
AVC
AFC
8-14
Production Relationships
• Marginal cost and diminishing returns• Marginal cost and marginal product• Marginal cost and average variable
cost• Marginal cost and average total cost• Production curves and cost curves• Shifts in cost curves
8-15
Ave
rag
e P
rod
uct
an
dM
arg
inal
Pro
du
ctC
ost
(D
olla
rs)
Graphical Relationships
MPAP
MCAVC
Quantity of Output
Quantity of Labor
Production Curves
Cost Curves
8-16
Long-Run Production Costs
• Choose your plant size
• Minimize ATC
• Different ATC curves–Short run
• Long run ATC–Envelope of short run ATC
8-17
Long-Run ATC Curve
Ave
rag
e T
ota
l C
ost
sATC-1
ATC-2
ATC-3 ATC-4
ATC-5
Output
Any number of short-run optimum size cost curves can be constructed
8-18
Long-Run ATC Curve
Long-RunATC
Ave
rag
e T
ota
l C
ost
sATC-1
ATC-2
ATC-3 ATC-4
ATC-5
Output
The long-run ATC curve just“envelopes” the short run ATCs
8-19
Long Run Production Cost
• Economies of Scale–Labor specialization
–Managerial specialization
–Efficient capital
• Diseconomies of Scale
• Constant Returns to Scale
8-20
Long-Run ATC Shapes
Output
Long-run ATC curve where economiesof scale exist
Ave
rag
e T
ota
l C
ost
s
Long-RunATC
EconomiesOf Scale
Constant ReturnsTo Scale
DiseconomiesOf Scale
q1 q2
8-21
Output
Long-run ATC curve where costs arelowest only when large numbers areparticipating
Ave
rag
e T
ota
l C
ost
sEconomies
Of ScaleDiseconomies
Of Scale
Long-RunATC
Long-Run ATC Shapes
8-22
Output
Long-run ATC curve where economiesof scale exist, are exhausted quickly,and turn back up substantially
Ave
rag
e T
ota
l C
ost
s
Long-RunATC
EconomiesOf Scale
DiseconomiesOf Scale
Long-Run ATC Shapes
8-23
Industry Structure
• Minimum efficient scale (MES)• Natural monopoly• Applications and illustrations
–Price of corn–Successful start-up firms–The Verson stamping machine–The daily newspaper–Aircraft and concrete plants
8-24
Sunk Costs
• Irrelevant in decision making• Cannot be recovered• Do not affect marginal
benefit and marginal cost• Firm example:
–R&D costs
8-25
Key Terms
• economic (opportunity) cost
• explicit costs• implicit costs• normal profit• economic profit• short run• long run• total product (TP)• marginal product (MP)• average product (AP)• law of diminishing returns• fixed costs
• variable costs• total cost• average fixed cost (AFC)• average variable cost (AVC)• average total cost (ATC)• marginal cost (MC)• economies of scale• diseconomies of scale• constant returns to scale• minimum efficient scale
(MES)• natural monopoly
8-26
Next Chapter Preview…
PureCompetition
8-27