Chapter 10: Externalities and Public Goods

Externalities and Public Goods

Identifying Externalities

  • Externality Definition:
    • A side effect of an activity that affects bystanders whose interests are not taken into account.
    • Ignoring these interests leads to market failure, resulting in inefficient outcomes that are not in society’s best interest.

Types of Externalities:

  • Negative Externality:

    • Harmful side effects imposed on bystanders.
    • Examples:
    • Parking two spaces takes away parking from others.
    • Secondhand smoke from smoking near others.
    • Distractions caused by phone use in class.

  • Positive Externality:

    • Beneficial side effects that generate benefits for others.
    • Examples:
    • Exercising leads to healthier individuals, benefiting health insurers.
    • Preparing for a study group benefits peers.
    • Planting a flower garden enhances neighborhood beauty.

Apparent Conflicts

  • Private vs. Social interests

    • Private interest refers to personal costs and benefits.

    • Societal interest includes all costs and benefits.

    • The presence of externalities creates a conflict, leading to market failure where societal best interests are not reflected in market outcomes.

Market Implications of Externalities

  • Negative Externalities Lead to Overproduction:

    • Marginal Private Costs (MPC) are less than Marginal Social Costs (MSC).

  • Positive Externalities Lead to Underproduction:

    • Marginal Private Benefits (MPB) are less than Marginal Social Benefits (MSB).

Analyzing Externalities

  1. Forecast Equilibrium Quantity:
    • Identify market equilibrium based on supply and demand.
  2. Assess Externalities:
    • Identify if the externality is negative or positive.
  3. Find Socially Optimal Quantity:
    • Optimal where Marginal Social Benefit equals Marginal Social Cost.
  4. Compare Equilibrium vs. Social Optimal:
    • Determine overproduction or underproduction.

Solving Externality Problems

  • Private Bargaining (Coase Theorem):

    • If bargaining costs are low and property rights are clear, individuals can negotiate to resolve externality problems.

  • Corrective Taxes and Subsidies:

    • Negative Externality: Implement a tax equal to the external cost to reduce activity.
    • Positive Externality: Implement a subsidy equal to the external benefit to increase activity.

  • Cap and Trade:

    • Issues permits that can be traded among firms, thus incentivizing reductions in pollution.

  • Laws, Rules, Regulations:

    • Implement legislation to reduce harmful behaviors (e.g., noise regulations).

Public Goods and Common Resources

Characteristics of Goods

  • Excludable: Can prevent others from using it.
  • Rival: One person’s use diminishes the value for others.
  • Nonexcludable: Cannot easily prevent access.
  • Nonrival: Use does not diminish availability for others.

Public Goods

  • Nonexcludable and nonrival goods lead to the free-rider problem, resulting in underproduction because everyone benefits without paying.

Common Resources

  • Rival and nonexcludable goods lead to the tragedy of the commons, as individuals exploit resources for personal gain, leading to overconsumption.

Solutions for Public Goods

  • Government Support:
    • Direct provision or funding of public goods to mitigate free-rider problems.

Solutions for Common Resources

  • Assign Ownership Rights:
    • Grants individuals property rights, incentivizing sustainable use of resources.