🛒Principles of Microeconomics Unit 13 – Positive Externalities & Public Goods

Key Concepts and Definitions

• Externalities occur when the actions of an individual or firm affect the well-being of a third party without compensation
• Positive externalities provide benefits to third parties not directly involved in the market transaction
• Public goods are non-excludable (individuals cannot be effectively excluded from use) and non-rivalrous (use by one individual does not reduce availability to others)
• Free-rider problem arises when individuals can benefit from a good or service without paying for it
• Social benefit equals private benefit plus external benefit
• Social cost equals private cost plus external cost
• Marginal social benefit (MSB) is the additional benefit to society from producing one more unit of a good or service
• Marginal social cost (MSC) is the additional cost to society from producing one more unit of a good or service

Types of Externalities and Public Goods

• Positive production externalities occur when the production of a good or service generates external benefits (education, research and development)
• Positive consumption externalities occur when the consumption of a good or service generates external benefits (vaccinations, beautiful gardens)
• Negative production externalities occur when the production of a good or service generates external costs (pollution, noise)
• Negative consumption externalities occur when the consumption of a good or service generates external costs (secondhand smoke, traffic congestion)
• Pure public goods are both non-excludable and non-rivalrous (national defense, lighthouses)
• Impure public goods are either non-excludable or non-rivalrous, but not both (cable television, public parks)
  • Club goods are excludable but non-rivalrous (private golf courses)
  • Common resources are non-excludable but rivalrous (fishing grounds)

Market Failure and Inefficiency

• Market failure occurs when the allocation of goods and services is not efficient, often due to externalities or public goods
• In the presence of positive externalities, the market underproduces the good or service compared to the socially optimal level
  • The marginal social benefit (MSB) is greater than the marginal private benefit (MPB)
• In the presence of negative externalities, the market overproduces the good or service compared to the socially optimal level
  • The marginal social cost (MSC) is greater than the marginal private cost (MPC)
• Public goods are often underprovided by the market due to the free-rider problem
• Inefficiency arises when the marginal social benefit does not equal the marginal social cost (MSB ≠ MSC)
• Deadweight loss is the reduction in economic surplus due to market inefficiency

Government Intervention Strategies

• Pigouvian taxes can be imposed on activities that generate negative externalities to internalize the external cost
  • The optimal tax rate equals the marginal external cost at the socially optimal quantity
• Subsidies can be provided for activities that generate positive externalities to encourage their production or consumption
  • The optimal subsidy rate equals the marginal external benefit at the socially optimal quantity
• Regulation can be used to set standards, limits, or requirements for activities that generate externalities (emissions standards, zoning laws)
• Government provision of public goods can ensure an adequate supply of goods and services that the market fails to provide efficiently (infrastructure, education)
• Property rights can be assigned to create incentives for efficient use of resources and internalize externalities (tradable pollution permits)

Cost-Benefit Analysis

• Cost-benefit analysis is a systematic approach to estimating the strengths and weaknesses of alternative policies or projects
• Benefits and costs are expressed in monetary terms and adjusted for the time value of money
• The net present value (NPV) is the difference between the present value of benefits and the present value of costs
  • A positive NPV indicates that the benefits outweigh the costs
• The benefit-cost ratio (BCR) is the ratio of the present value of benefits to the present value of costs
  • A BCR greater than 1 indicates that the benefits outweigh the costs
• Sensitivity analysis is used to assess how changes in key assumptions or variables affect the results of the cost-benefit analysis
• Distributional effects and non-monetary impacts should also be considered in the decision-making process

Real-World Examples and Case Studies

• Positive education externalities: Increased education levels can lead to higher productivity, innovation, and social cohesion
• Negative pollution externalities: Industrial activities can generate air and water pollution, imposing health and environmental costs on society
• Public goods in healthcare: Vaccination programs provide benefits to both the vaccinated individuals and the broader community through herd immunity
• Congestion pricing: Cities like London and Singapore have implemented congestion charges to internalize the external costs of traffic congestion
• Carbon taxes and cap-and-trade systems: These policies aim to reduce greenhouse gas emissions by putting a price on carbon
• Fisheries management: Individual transferable quotas (ITQs) can be used to prevent overfishing and ensure sustainable use of common resources

Policy Implications and Debates

• Determining the optimal level of government intervention can be challenging due to information asymmetries and political considerations
• The distribution of costs and benefits across different groups in society should be taken into account when designing policies
• The Coase Theorem suggests that externalities can be internalized through private negotiations if property rights are well-defined and transaction costs are low
  • In practice, high transaction costs and strategic behavior often necessitate government intervention
• The choice between price-based (taxes and subsidies) and quantity-based (regulation and tradable permits) instruments depends on factors such as uncertainty and administrative costs
• Behavioral economics insights can be used to design more effective policies that account for bounded rationality and social norms
• International cooperation is often necessary to address global public goods and transboundary externalities (climate change, ozone depletion)

Review Questions and Practice Problems

1. Explain the difference between private and social costs in the presence of negative externalities. Provide an example.
2. How do positive externalities lead to market underprovision of a good or service? Illustrate your answer using a supply and demand diagram.
3. Describe two key characteristics of public goods and explain why they lead to market failure.
4. Suppose a factory produces widgets and emits pollution that imposes an external cost of $10 per unit of output. The marginal private cost of production is given by MPC = 2Q, where Q is the quantity of widgets produced. The marginal private benefit is given by MPB = 100 - Q. Calculate the socially optimal level of output and the optimal Pigouvian tax rate.
5. Discuss the advantages and disadvantages of government provision of public goods compared to private provision.
6. Explain the concept of the free-rider problem and provide an example of how it can lead to the underprovision of a public good.
7. Describe the steps involved in conducting a cost-benefit analysis for a proposed government project. What are some limitations of this approach?
8. Discuss the policy implications of the Coase Theorem for dealing with externalities. Under what conditions is private negotiation likely to be effective?