Externalities, Environmental Policy, and Public Goods: Microeconomics Chapter 5 Study Notes

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Externalities, Environmental Policy, and Public Goods

Introduction to Externalities

Externalities are unintended side effects of economic activities that affect third parties not directly involved in the transaction. They are central to understanding market failures and the role of government intervention in microeconomics.

Externality: A benefit or cost that affects someone who is not directly involved in the production or consumption of a good or service.
Example: Pollution from a factory affects nearby residents who are not part of the production process.
Side-effect: Externalities are often described as side-effects of economic activity.

The Effect of Externalities on Economic Efficiency

Externalities disrupt the efficient allocation of resources in markets, leading to either overproduction or underproduction of goods and services.

Private cost: The cost borne by the producer of a good or service.
Social cost: The total cost of producing a good or service, including both private and external costs.
Negative externality: Raises the social cost above the private cost (e.g., pollution).
Positive externality: Raises the social benefit above the private benefit (e.g., education).

Energy Production and Externalities

Energy production is a key industry in modern economies, often associated with significant externalities, especially pollution.

Sellers: Face increasing marginal costs to produce electricity.
Buyers: Experience decreasing marginal benefits from additional electricity use.
Market supply and demand curves are shaped by these interactions.

Cost of Electricity Production

Electricity firms consider private costs such as buildings, equipment, fuel, and labor when making production decisions. However, pollution increases the social cost beyond the private cost.

Private costs: Direct expenses incurred by firms.
Social costs: Include private costs plus external costs like pollution.

Graphical Analysis: Pollution and Economic Efficiency

Market equilibrium based on private costs leads to overproduction when negative externalities are present. The socially optimal level of production occurs where marginal social cost equals marginal benefit.

Supply curve Sp: Represents marginal private cost.
Supply curve Ss: Represents marginal social cost.
Deadweight loss: The cost to society from overproduction due to externalities.

Externalities in Consumption

Externalities can also arise from consumption, affecting the social benefit received from a good or service.

Private benefit: Benefit received by the consumer.
Social benefit: Total benefit, including external benefits.
Positive externality example: Education increases societal welfare beyond the private benefit to students.
Negative externality example: Cigarette consumption imposes health costs on others.

Market Failure and Deadweight Loss

Market failure occurs when externalities prevent markets from producing the efficient quantity of output, resulting in deadweight loss.

Overproduction: With negative externalities.
Underproduction: With positive externalities.
Deadweight loss: The greater the externality, the larger the deadweight loss.

Property Rights and Externalities

Externalities often arise due to incomplete or unenforced property rights. Clearly defined property rights can help resolve externality problems.

Property rights: The rights to exclusive use of property, including the right to buy or sell it.
Example: If a farmer owns a stream, they can prevent pollution or charge for its use.

The Coase Theorem

The Coase theorem states that private parties can solve externality problems through bargaining, provided property rights are assigned and transaction costs are low.

Transaction costs: Costs incurred in making an agreement.
Key insight: The allocation of property rights does not affect the efficient outcome, as long as rights are enforceable and transaction costs are low.
Example: Bargaining between a farmer and a paper mill over stream pollution.

Government Policies for Externalities

Governments use various policies to address externalities and restore economic efficiency.

Pigovian taxes: Taxes imposed to correct negative externalities (named after Arthur Pigou).
Subsidies: Payments to encourage production or consumption of goods with positive externalities.
Command-and-control policies: Regulations that set quantitative limits or require specific technologies.
Cap-and-trade: Tradable emissions allowances to achieve pollution reduction at lowest cost.

Corrective Taxes and Subsidies

Pigovian taxes and subsidies are designed to align private incentives with social efficiency.

Pigovian tax formula:

Example: Carbon tax to reduce greenhouse gas emissions.

Alternatives to Taxation: Cap-and-Trade

Cap-and-trade systems set a total allowable level of emissions and allow firms to trade permits, achieving pollution reduction efficiently.

Tradable emissions allowances: Firms with low abatement costs sell permits to firms with high abatement costs.
Example: U.S. sulfur dioxide cap-and-trade program.

Criticism of Cap-and-Trade

Some environmentalists argue that cap-and-trade gives firms a license to pollute, but economists note that pollution has opportunity costs and should be priced appropriately.

Global Warming and Policy Responses

Global warming is a major externality with significant economic costs. Policy responses include Pigovian taxes, cap-and-trade, and subsidies for renewable energy.

Carbon tax: Economists recommend a tax equal to the marginal social cost of emissions.
International coordination: Global problems require coordinated solutions, such as the Paris Climate Accords.

Categories of Goods

Goods can be classified based on whether their consumption is rival and/or excludable. This affects how efficiently markets provide them.

	Excludable	Nonexcludable
Rival	Private Goods Examples: Big Macs, Running shoes	Common Resources Examples: Tuna in the ocean, Public pastureland
Nonrival	Quasi-Public Goods Examples: Cable TV, Toll road	Public Goods Examples: National defense, Court system

Efficient Provision of Goods

Markets efficiently provide private goods but struggle with public goods, common resources, and quasi-public goods due to free-rider problems and overconsumption.

Free rider problem: People benefit from public goods without paying.
Tragedy of the commons: Overuse of common resources due to lack of exclusion.

Constructing Demand Curves

Demand curves for private and public goods are constructed differently.

Private goods: Market demand is the horizontal sum of individual quantities demanded at each price.
Public goods: Market demand is the vertical sum of individual willingness to pay for each quantity.

Optimal Quantity of Public Goods

The efficient quantity of a public good is where the market demand curve intersects the supply curve. Cost-benefit analysis is often used to estimate the correct amount.

Efficient Consumption of Common Resources

Common resources tend to be overconsumed, leading to deadweight loss. This is a form of negative externality known as the tragedy of the commons.

Solution: Pigovian taxes, quotas, or tradable permits can help regulate use.

Solutions to the Tragedy of the Commons

When property rights cannot be enforced, solutions include community norms for small groups or legal restrictions for larger groups.

Community norms: Effective in small, localized settings.
Legal restrictions: Necessary for large-scale or widely dispersed resources.

Additional info: These notes expand on brief points from the slides and textbook images, providing definitions, examples, and academic context for key microeconomics concepts related to externalities, public goods, and environmental policy.