Transcript Externalities and the Environment

Chapter 2: Externalities and the Environment
Chapter 2
McGraw-Hill/Irwin
Externalities
and the Environment
Copyright © 2009 by The McGraw-Hill Companies, Inc. All rights reserved.
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Chapter 2: Externalities and the Environment
Introduction
The economist’s approach to pollution
Economic analysis of a pollution tax and
tradable permits
Applications: Acid rain and global warming
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Chapter 2: Externalities and the Environment
Externalities and the Environment
Negative externality
Positive externality
Exists whenever a producer or
consumer does not have to pay
for a cost he generates.
• Examples: air pollution,
water pollution, or noise
pollution
Exists whenever a producer or
consumer does not receive a
payment for a benefit he generates.
• Examples: immunizations or
improving your home.
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Chapter 2: Externalities and the Environment
The Economist’s Approach to Pollution
Pollution is an example of a market failure.
• An allocation of resources
that is not socially optimal.
When externalities exist, there is a failure of property rights.
Solution?
Establish property rights and
charge a price for its use.
• government
Who can have property rights? • private firms
• individuals
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Chapter 2: Externalities and the Environment
The Economist’s Approach to Pollution
If the government has property rights,
how do they charge a price?
TAXES
PERMITS
Charging polluters a price forces them to
internalize the externality.
A private solution (Coase’s prescription) is possible if:
1. Property rights exist
2. A small number of citizens are harmed
3. There are low transaction costs
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Chapter 2: Externalities and the Environment
Trade-off between
Environmental Quality and Output
Figure 2.1
Environmental
Quality
Maximum environmental quality
a
b
Increase in environmental quality
and a decrease in output
c
d
e
f
Maximum output with zero
environmental quality
Output
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Chapter 2: Externalities and the Environment
Trade-off between
Environmental Quality and Output
The Virtues of Pollution Prices
Allocation problem
• Command and control method
• Tax method
• Polluters with different technological options
• Permit method
Objections to pollution prices and economist’s responses
• Pollution price is a “license to pollute”
• Pollution prices will raise product prices
• Pollution taxes will raise the tax burden on
the population
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Chapter 2: Externalities and the Environment
Charging a Price vs. Mandating or
Subsidizing Clean Technologies
Economists recommend using pollution prices and
oppose mandating or subsidizing clean technologies.
WHY? • Pollution prices stimulate clean technologies
• Mandates lead to high costs for consumers
- CAFE standards
• Subsidies lead to a distorted playing field among
potential alternatives
• Political lobbying for subsidies cause distortion
• Clean alternatives is not always the socially optimal
response
• Subsidies require raising taxes
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Chapter 2: Externalities and the Environment
A Pollution Tax
The right tax generates the right quantity of a polluting good
Figure 2.2
MSC
P
J
I
S (MPC)
MD
$2.50
MSC = MPC + MD
K
H
D (MB)
80
100
Gasoline
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Chapter 2: Externalities and the Environment
A Pollution Tax
Levy a corrective tax (Pigouvian tax) equal to the MD
Figure 2.3
S` (MSC`)
P
J
I
S (MPC)
Social optimum quantity
is where MSC = MB
at 80 units of gasoline
T
$2.50
K
H
D (MB)
80
100
Gasoline
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Chapter 2: Externalities and the Environment
A Pollution Tax
An optimal tax confers a net benefit to society
Figure 2.4
P
MSC
J
S (MPC)
I
Gain in environmental
benefit = HIJK
Loss of output = HIK
$2.50
K
H
D (MB)
80
100
Net gain to society
= HIJK – HIK
= IJK
Gasoline
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Chapter 2: Externalities and the Environment
A Pollution Tax
Use pollution tax revenue to cut other taxes
• Pollution taxes as revenue replacers
• Different ways of returning the tax revenue to the
private sector will have different effects
Tax emissions, not the polluting good
• Whenever feasible, levy the tax per unit of
pollution – per emission – not per unit of
polluting good
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Chapter 2: Externalities and the Environment
$200
A Pollution Tax
MACH
• To minimize cost, levy the same
tax on all firms emitting pollutant X
Figure 2.5
2 firms with different MACs
$100
$60
$50
$40
Without government policy,
each firm pollutes 50 units.
MACL
$25
$20
10
25
30
35
40 45 50
Emissions
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Chapter 2: Externalities and the Environment
$200
A Pollution Tax
MACH
Figure 2.5
• To minimize cost, levy the same
tax on all firms emitting pollutant X
• Marginal damage and tax rate is constant at $40
• Firms will abate until MAC = T
• Equi-marginal principle
$100
$60
$50
$40
• After the tax is levied,
MACH will abate 10 units and
MACL will abate 40 units
MACL
MD = T
$25
$20
10
25
30
35
• After tax, total
emission is
50 units
40 45 50
Emissions
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Chapter 2: Externalities and the Environment
Tradable Permits
CAP and TRADE
• Cap – supply of emissions permits is fixed
• Trade – permits can be bought and sold in
the market throughout the year
How do firms get the permits?
1. Government sells permits
2. Government gives the permits away
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Chapter 2: Externalities and the Environment
Tradable Permits – Government sells permits
$200
DH = MACH
• Each firm’s permit demand
curve is its MAC curve
• The government decided
to supply 50 pollution permits
S
$100
$60
$50
$40
DL= MACL
D = market demand
$25
$20
10
25
30
35
40 45 50
75
Permits
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Chapter 2: Externalities and the Environment
Tradable Permits – Government sells permits
$200
DH
What is the optimal permit price?
• Price where S = D
S
$100
$60
$50
$40
Tentative prices
• P = $50 is too high
• P = $20 is too low
• P = $40 results in the
desired outcome
• Tax vs. permit
• A hybrid policy
DL
P=$50
P=$40
D
$25
$20
10
25
30
35
40 45 50
75
P=$20
Permits
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Chapter 2: Externalities and the Environment
Tradable Permits –
Government gives the permits away
Just like selling permits or levying a tax,
giving permits to polluting firms will reduce pollution.
• The supply curve for each polluting good will shift to the
left
• The price of polluting goods will increase
But, giving the permits away can lead to higher output
and emissions than is socially optimal in the long run.
Which is best?
• Firms want the government to give permits
• Taxpayers want the government to sell permits
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Chapter 2: Externalities and the Environment
Application: Tradable Permits for Sulfur
Dioxide to Reduce Acid Rain
Sulfur dioxide causes acid rain
Old policy – a maximum sulfur dioxide emission rate for
new coal-burning electricity generating firms.
New policy – tradable permits are given to electric power
plants
• Clean Air Act Amendments of 1990
• Plants can then buy and sell permits an needed
• Total emissions have fallen with the new policy
• Two issues: long run issue, and tax revenue issue
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Chapter 2: Externalities and the Environment
Application: A Carbon Tax or Tradable
Permits to Reduce Global Warming
Carbon emissions cause global warming
• A carbon tax treaty
• A carbon tradable permits treaty
• A hybrid carbon treaty: a permit system
with a safety valve
• The political challenge
Policy decision – carbon tax or carbon permits?
Policy decision – how can low-income countries be
induced to participate?
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Chapter 2: Externalities and the Environment
Summary
The Economist’s approach to pollution
Economic analysis of a pollution tax and
tradable permits
Applications: Acid rain and global warming
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Chapter 2: Externalities and the Environment
Preview of Chapter 3:
Public Goods and Political Economy
The concept of a public good
Political economy
The behavior of the government
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