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

Externalities and Economic Efficiency

Introduction to Externalities

Externalities are unintended side-effects of economic activities that affect third parties not directly involved in the production or consumption of a good or service. They can be either positive or negative and have significant implications for economic efficiency.

• Externality: A benefit or cost that affects someone who is not directly involved in the activity.

• Example: Pollution from a factory affects nearby residents (negative externality); education benefits society beyond the student (positive externality).

• Side-effect: Externalities are often described as side-effects of economic actions.

The Effect of Externalities: Production

Externalities in production can cause a divergence between private and social costs, leading to inefficiency in the market outcome.

• 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 production externality: Occurs when social cost exceeds private cost (e.g., pollution).

• Formula:

$\text{Social Cost} = \text{Private Cost} + \text{External Cost}$

• Economic inefficiency: Too much of the good is produced when negative externalities are present.

The Effect of Externalities: Consumption

Externalities in consumption can cause a difference between private and social benefits, affecting the efficient allocation of resources.

• Private benefit: The benefit received by the consumer.

• Social benefit: The total benefit from consumption, including external benefits.

• Positive consumption externality: Social benefit exceeds private benefit (e.g., education).

• Negative consumption externality: Social benefit is less than private benefit (e.g., smoking).

• Formula:

$\text{Social Benefit} = \text{Private Benefit} + \text{External Benefit}$

• Economic inefficiency: Too little of the good is produced when positive externalities are present.

Private Solutions to Externalities: The Coase Theorem

Property Rights and Bargaining

Private solutions to externalities rely on well-defined and enforceable property rights, allowing parties to negotiate and reach efficient outcomes.

• Property rights: The rights to the exclusive use of property, including the right to buy or sell it.

• Coase Theorem: If property rights are assigned and transaction costs are low, private bargaining can solve the externality problem and achieve economic efficiency.

• Transaction costs: The costs in time and resources to negotiate and enforce agreements.

• Key insight: The allocation of property rights does not affect the efficient outcome, only the distribution of costs and benefits.

Example: Farmer and Paper Mill

• If the farmer owns the stream, they can prevent pollution or allow it for a fee.

• If the paper mill owns the stream, the farmer can pay to reduce pollution.

• Efficient pollution level is where marginal benefit equals marginal cost.

$\text{Marginal Benefit of Pollution Reduction} = \text{Marginal Cost of Pollution Reduction}$

Government Policies to Deal with Externalities

Corrective Taxes and Subsidies (Pigovian Taxes/Subsidies)

Governments can address externalities through taxes and subsidies designed to align private incentives with social efficiency.

• Pigovian tax: A tax imposed to correct a negative externality (e.g., carbon tax).

• Pigovian subsidy: A subsidy to encourage activities with positive externalities (e.g., education grants).

• Efficient outcome: Achieved when the tax or subsidy equals the external cost or benefit.

$\text{Optimal Tax} = \text{Marginal External Cost}$

$\text{Optimal Subsidy} = \text{Marginal External Benefit}$

• Example: Taxing cigarettes due to shared health costs; subsidizing college education for societal benefits.

Command-and-Control Policies

Traditional regulatory approaches involve setting quantitative limits or requiring specific technologies to reduce externalities.

• Command-and-control: Government sets limits on emissions or mandates pollution control devices.

• Example: Requiring catalytic converters in cars.

• Limitation: May not be cost-effective if firms have different abatement costs.

Market-Based Policies: Tradable Emissions Allowances (Cap-and-Trade)

Market-based approaches use tradable permits to achieve pollution reduction at the lowest cost.

• Cap-and-trade: Government sets a cap on total emissions and distributes allowances that can be traded among firms.

• Efficiency: Firms with low abatement costs sell permits to those with high costs, minimizing total cost of pollution reduction.

• Example: U.S. sulfur dioxide cap-and-trade program.

Four Categories of Goods

Classifying Goods: Rivalry and Excludability

Goods are categorized based on whether consumption is rival and/or excludable, affecting how efficiently markets provide them.

• Rivalry: One person's consumption reduces availability for others.

• Excludability: Non-payers can be prevented from consuming the good.

	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 and Market Failure

• Markets efficiently provide private goods but struggle with public goods and common resources due to free-rider and overuse problems.

• Free rider problem: People benefit from public goods without paying, leading to underprovision.

• Tragedy of the commons: Overuse of common resources due to lack of exclusion.

• Quasi-public goods: May exclude too many people, reducing efficiency.

Constructing Demand Curves

• 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.

Efficient Consumption of Common Resources

• Common resources are overconsumed because individuals ignore the external cost imposed on others.

• Solution: Pigovian taxes, quotas, or tradable permits can help achieve efficient use.

• Tragedy of the commons: Occurs when property rights are not well-defined or enforceable.

Solutions to the Tragedy of the Commons

• Community norms and traditions can restrict access in small, localized settings.

• Legal restrictions, taxes, quotas, and permits are needed for larger or more dispersed resources.

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