Download - Chapter 7
Chapter 7Profit Maximization
and Perfect Competition
Profit Maximization and Perfect Competition
Slide 1Chapter 7
Chapter 7 Slide 2
Perfectly Competitive Markets
Characteristics of Perfectly Competitive Markets
1) Price taking
2) Product homogeneity
3) Free entry and exit
Chapter 7 Slide 3
Perfectly Competitive Markets
Price Taking
The individual firm sells a very small share of the total market output and, therefore, cannot influence market price.
The individual consumer buys too small a share of industry output to have any impact on market price.
Chapter 7 Slide 4
Perfectly Competitive Markets
Product Homogeneity
The products of all firms are perfect substitutes.
Examples
Agricultural products, oil, copper, iron,
Chapter 7 Slide 5
Perfectly Competitive Markets
Free Entry and Exit
Buyers can easily switch from one supplier to another.
Suppliers can easily enter or exit a market.
Chapter 7 Slide 6
Profit Maximization
Do firms maximize profits?Revenue maximizationDividend maximizationShort-run profit maximization
Chapter 7 Slide 7
Profit Maximization
Do firms maximize profits?
Implications of non-profit objectiveOver the long-run investors would not
support the companyWithout profits, survival unlikelyLong-run profit maximization is valid
Chapter 7 Slide 8
Marginal Revenue, Marginal Cost,and Profit Maximization
Determining the profit maximizing level of outputProfit ( ) = Total Revenue - Total Cost
Total Revenue (R) = Pq
Total Cost (C) = Cq
Therefore:
)()()( qCqRq
Chapter 7 Slide 9
Profit Maximization in the Short Run
0
Cost,Revenue,
Profit($s per year)
Output (units per year)
R(q)Total Revenue
Slope of R(q) = MR
Chapter 7 Slide 10
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
Profit Maximization in the Short Run
C(q)
Total Cost
Slope of C(q) = MC
Chapter 7 Slide 11
Marginal revenue is the additional revenue from producing one more unit of output.
Marginal cost is the additional cost from producing one more unit of output.
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 12
Comparing R(q) and C(q)
Output levels: 0- q0:
C(q)> R(q) Negative profit
FC + VC > R(q) MR > MC
Indicates higher profit at higher output 0
Cost,Revenue,
Profit($s per year)
Output (units per year)
R(q)
C(q)
A
B
q0 q*
)(q
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 13
Comparing R(q) and C(q) Question: Why is profit
negative when output is zero?
Marginal Revenue, Marginal Cost,and Profit Maximization
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Chapter 7 Slide 14
Comparing R(q) and C(q)
Output levels: q0 - q*
R(q)> C(q) MR > MC
Indicates higher profit at higher output
Profit is increasing
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 15
Comparing R(q) and C(q)
Output level: q*
R(q)= C(q) MR = MC Profit is maximized
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 16
Question
Why is profit reduced when producing more or less than q*?
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 17
Comparing R(q) and C(q)
Output levels beyond q*: R(q)> C(q) MC > MR Profit is decreasing
Marginal Revenue, Marginal Cost,and Profit Maximization
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Chapter 7 Slide 18
Therefore, it can be said:
Profits are maximized when MC = MR.
Marginal Revenue, Marginal Cost,and Profit Maximization
R(q)
0
Cost,Revenue,
Profit$ (per year)
Output (units per year)
C(q)
A
B
q0 q*
)(q
Chapter 7 Slide 19
C - R
Marginal Revenue, Marginal Cost,and Profit Maximization
q
R MR
q
CMC
Chapter 7 Slide 20
orq
C
q
R 0
q
: whenmaximized are Profits
MC(q)MR(q)
MCMR
thatso0
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 21
The Competitive Firm
Price taker
Market output (Q) and firm output (q)
Market demand (D) and firm demand (d)
R(q) is a straight line
Marginal Revenue, Marginal Cost,and Profit Maximization
Demand and Marginal Revenue Facedby a Competitive Firm
Output (bushels)
Price$ per bushel
Price$ per bushel
Output (millions of bushels)
d$4
100 200 100
Firm Industry
D
$4
Slide 22Chapter 7
Chapter 7 Slide 23
The Competitive Firm
The competitive firm’s demand Individual producer sells all units for $4
regardless of the producer’s level of output.
If the producer tries to raise price, sales are zero.
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 24
The Competitive Firm
Profit MaximizationMC(q) = MR = P
Marginal Revenue, Marginal Cost,and Profit Maximization
Chapter 7 Slide 25
Choosing Output in the Short Run
We will combine production and cost analysis with demand to determine output and profitability.
Chapter 7 Slide 26
q0
Lost profit forq1 < q*
Lost profit forq2 > q*
q1 q2
A Competitive FirmMaking a Positive Profit
10
20
30
40
Price($ per
unit)
0 1 2 3 4 5 6 7 8 9 10 11
50
60MC
AVC
ATCAR=MR=P
Outputq*
At q*: MR = MC
ABCD
D A
BC
q1 : MR > MC andq2: MC > MR andq0: MC = MR but
MC falling
Chapter 7 Slide 27
Would this producercontinue to produce with a loss?
A Competitive FirmIncurring Losses
Price($ per
unit)
Output
AVC
ATCMC
q*
P = MR
B
F
C
A
E
DAt q*: MR = MCand P < ATCor ABCD
Chapter 7 Slide 28
Choosing Output in the Short Run
Summary of Production Decisions
Profit is maximized when MC = MR
If P > ATC the firm is making profits.
If AVC < P < ATC the firm should produce at a loss.
If P < AVC < ATC the firm should shut-down.
Chapter 7 Slide 29
A Competitive Firm’sShort-Run Supply Curve
Price($ per
unit)
Output
MC
AVC
ATC
P = AVCWhat happens
if P < AVC?
P2
q2
P1
q1
The firm chooses theoutput level where MR = MC,as long as the firm is able to
cover its variable cost of production.
Chapter 7 Slide 30
Observations:P = MRMR = MCP = MC
Supply is the amount of output for every possible price. Therefore:If P = P1, then q = q1
If P = P2, then q = q2
A Competitive Firm’sShort-Run Supply Curve
Chapter 7 Slide 31
Price($ per
unit)
MC
Output
AVC
ATC
P = AVC
P1
P2
q1 q2
S = MC above AVC
A Competitive Firm’sShort-Run Supply Curve
Shut-down
Chapter 7 Slide 32
Observations:Supply is upward sloping due to
diminishing returns.
Higher price compensates the firm for higher cost of additional output and increases total profit because it applies to all units.
A Competitive Firm’sShort-Run Supply Curve
Chapter 7 Slide 33
Firm’s Response to an Input Price ChangeWhen the price of a firm’s product
changes, the firm changes its output level,
A Competitive Firm’sShort-Run Supply Curve
Chapter 7 Slide 34
MC2
q2
Input cost increases and MC shifts to MC2
and q falls to q2.
MC1
q1
The Response of a Firm toa Change in Input Price
Price($ per
unit)
Output
$5
Savings to the firmfrom reducing output
Chapter 7 Slide 35
The Short-Run Market Supply Curve
Elasticity of Market Supply
)//()/( PPQQEs
Chapter 7 Slide 36
Perfectly inelastic short-run supply arises when the industry’s plant and equipment are so fully utilized that new plants must be built to achieve greater output.
Perfectly elastic short-run supply arises when marginal costs are constant.
The Short-Run Market Supply Curve
Chapter 7 Slide 37
Producer Surplus in the Short RunThe producer surplus is the sum over all
units produced of the difference between the market price of the good and the marginal cost of production.
The Short-Run Market Supply Curve
Chapter 7 Slide 38
AA
DD
BB
CC
ProducerProducerSurplusSurplus
Alternatively, VC is thesum of MC or ODCq* .R is P x q* or OABq*.Producer surplus =
R - VC or ABCD.
Producer Surplus for a Firm
Price($ per
unit ofoutput)
Output
AVCAVCMCMC
00
PP
qq**
At q* MC = MR.Between 0 and q ,
MR > MC for all units.
Chapter 7 Slide 39
Producer Surplus in the Short-Run
The Short-Run Market Supply Curve
VC- R PS Surplus Producer
FC - VC - R Profit
Chapter 7 Slide 40
DD
PP**
QQ**
ProducerProducerSurplusSurplus
Market producer surplus isthe difference between P*
and S from 0 to Q*.
Producer Surplus for a Market
Price($ per
unit ofoutput)
Output
SS