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

Externalities, Environmental Policy, and Public Goods

Introduction to Externalities

Externalities are a central concept in microeconomics, describing situations where the actions of individuals or firms have effects on third parties not directly involved in the transaction. These effects can be either positive or negative and often lead to market inefficiency.

• Externality: A benefit or cost that affects someone who is not directly involved in the production or consumption of a good or service.

• Side-effect: Externalities are often referred to as side-effects of economic activity.

• Example: Pollution from a factory affects the health of nearby residents, even though they are not involved in the factory's operations.

The Effect of Externalities on Economic Efficiency

Externalities interfere with the efficient allocation of resources in a market. They create a divergence between private and social costs or benefits, 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 cost and any external cost.

• 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, especially electricity, is a key industry in the modern economy. The market for electricity involves sellers (producers) and buyers (consumers), whose interactions determine supply and demand curves. However, production often generates negative externalities such as pollution.

• Producers: Face increasing marginal costs to produce electricity.

• Consumers: Experience decreasing marginal benefits from additional electricity use.

• Market outcome: Without intervention, too much electricity may be produced due to unaccounted external costs.

Cost of Electricity Production

When firms produce electricity, they incur various private costs, but pollution increases the social cost beyond what firms consider in their decision-making.

• Private costs: Buildings, equipment, fuel, labor, etc.

• Social cost: Includes private costs plus the cost of pollution to society.

• Decision-making: Firms base production on private costs, leading to overproduction when external costs are ignored.

Graphical Analysis: Pollution and Economic Efficiency

Market supply and demand curves illustrate the impact of externalities. The supply curve based on private cost (Sp) differs from the supply curve based on social cost (Ss).

• Efficient output: Where marginal social cost equals marginal benefit.

• Market equilibrium: Occurs at a higher quantity when only private costs are considered, resulting in deadweight loss.

Equation:

• $MSC = MSB$ (Marginal Social Cost equals Marginal Social Benefit at efficient output)

Externalities in Consumption

Externalities can also arise from consumption, affecting the difference between private and social benefits.

• Private benefit: Benefit received by the consumer.

• Social benefit: Total benefit, including external benefits to others.

• Positive consumption externality: Education benefits society beyond the individual.

• Negative consumption externality: Cigarette smoking imposes health costs on others.

Market Failure and Deadweight Loss

Externalities lead to market failure, where the market does not produce the efficient quantity of output. The result is deadweight loss, representing lost welfare.

• Negative externalities: Overproduction and deadweight loss.

• Positive externalities: Underproduction and deadweight loss.

• Market failure: Failure to achieve allocative efficiency due to externalities.

Property Rights and Externalities

Externalities often arise due to incomplete or unenforced property rights. Clearly defined property rights can help internalize externalities and improve efficiency.

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

• Example: If a farmer owns a stream, they can prevent pollution or charge for its use.

The Coase Theorem

The Coase Theorem states that if property rights are well-defined and transaction costs are low, private bargaining can solve the externality problem, regardless of who holds the rights.

• Transaction costs: Costs incurred in making an economic exchange.

• Full information: Parties must know the costs and benefits involved.

• Implication: The allocation of property rights does not affect the efficient outcome.

Government Policies for Externalities

Governments can address externalities through taxes, subsidies, and regulations to achieve efficient outcomes.

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

• Subsidy: A payment to encourage production or consumption of goods with positive externalities (e.g., education subsidies).

• Command-and-control: Regulations that set limits or require specific technologies.

Corrective Taxes and Subsidies (Pigovian Taxes)

Pigovian taxes and subsidies are designed to internalize externalities and restore efficiency.

• Pigovian tax: Increases the cost of goods with negative externalities, reducing output to the efficient level.

• Pigovian subsidy: Encourages goods with positive externalities, increasing output to the efficient level.

• Example: British Columbia's carbon tax reduces emissions and income taxes.

Alternatives to Taxation: Cap-and-Trade and Command-and-Control

Other policy tools include cap-and-trade systems and direct regulation.

• Cap-and-trade: Government sets a cap on emissions and allows firms to trade permits, achieving pollution reduction at lowest cost.

• Command-and-control: Imposes limits or requires pollution control devices.

• Example: Sulfur dioxide cap-and-trade system in the U.S. (1990s).

Criticism of Cap-and-Trade

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

• Benefit of pollution: Allows for cheaper production, but must be balanced against environmental costs.

Global Warming and Policy Responses

Global warming is a major externality with worldwide impacts. Policy responses include taxes, subsidies, cap-and-trade, and international agreements.

• Carbon tax: Economists recommend taxing carbon emissions to reflect social costs.

• International coordination: Global problems require coordinated solutions (e.g., Paris Climate Accords).

Categories of Goods: Rivalry and Excludability

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 are efficient at providing private goods but struggle with public goods and common resources due to free-rider problems and overconsumption.

• Free rider: Someone who benefits from a good without paying for it.

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

Constructing Demand Curves for Private and Public Goods

The market demand curve for private goods is constructed by summing quantities at each price (horizontal summation), while for public goods, prices are summed at each quantity (vertical summation).

• Private goods: Add quantities demanded by each consumer at each price.

• Public goods: Add willingness to pay by each consumer at each quantity.

Optimal Quantity of Public Goods

The efficient quantity of a public good is where the market demand curve (sum of individual willingness to pay) intersects the supply curve. Cost-benefit analysis is often used to determine this level.

• Challenge: Consumers may not reveal true willingness to pay, complicating provision.

Efficient Consumption of Common Resources

Common resources are often 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.

• Community norms: May work for small, localized resources.

• Legal restrictions: Needed for larger or more dispersed resources.

Summary Table: Categories of Goods

Type	Rival?	Excludable?	Examples
Private Goods	Yes	Yes	Big Macs, Running shoes
Common Resources	Yes	No	Tuna in the ocean, Public pastureland
Quasi-Public Goods	No	Yes	Cable TV, Toll road
Public Goods	No	No	National defense, Court system

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