07-03-2011, 12:37 PM
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Externalities
• Recall: Adam Smith’s “invisible hand” of the marketplace leads self-interested buyers and sellers in a market to maximize the total benefit that society can derive from a market.
But market failures can still happen.
EXTERNALITIES AND MARKET INEFFICIENCY
• An externality refers to the uncompensated impact of one person’s actions on the well-being of a bystander.
• Externalities cause markets to be inefficient, and thus fail to maximize total surplus.
• An externality arises...
. . . when a person engages in an activity that influences the well-being of a bystander and yet neither pays nor receives any compensation for that effect.
• When the impact on the bystander is adverse, the externality is called a negative externality.
• When the impact on the bystander is beneficial, the externality is called a positive externality.
• Negative Externalities
• Automobile exhaust
• Cigarette smoking
• Barking dogs (loud pets)
• Loud stereos in an apartment building
• Positive Externalities
• Immunizations
• Restored historic buildings
• Research into new technologies
• Figure 1 The Market for Aluminum
• Negative externalities lead markets to produce a larger quantity than is socially desirable.
• Positive externalities lead markets to produce a larger quantity than is socially desirable.
• Welfare Economics: A Recap
The Market for Aluminum
• The quantity produced and consumed in the market equilibrium is efficient in the sense that it maximizes the sum of producer and consumer surplus.
• If the aluminum factories emit pollution (a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers.
• Welfare Economics: A Recap
• The Market for Aluminum
• For each unit of aluminum produced, the social cost includes the private costs of the producers plus the cost to those bystanders adversely affected by the pollution.
• Figure 2 Pollution and the Social Optimum
• Negative Externalities
• The intersection of the demand curve and the social-cost curve determines the optimal output level.
• The socially optimal output level is less than the market equilibrium quantity.
• Negative Externalities
• Internalizing an externality involves altering incentives so that people take account of the external effects of their actions.
• Negative Externalities
• Achieving the Socially Optimal Output
• The government can internalize an externality by imposing a tax on the producer to reduce the equilibrium quantity to the socially desirable quantity.
• Positive Externalities
• When an externality benefits the bystanders, a positive externality exists.
• The social value of the good exceeds the private value.
• Positive Externalities
• A technology spillover is a type of positive externality that exists when a firm’s innovation or design not only benefits the firm, but enters society’s pool of technological knowledge and benefits society as a whole.
• Figure 3 Education and the Social Optimum
• Positive Externalities
• The intersection of the supply curve and the social-value curve determines the optimal output level.
• The optimal output level is more than the equilibrium quantity.
• The market produces a smaller quantity than is socially desirable.
• The social value of the good exceeds the private value of the good.
• Positive Externalities
• Internalizing Externalities: Subsidies
• Used as the primary method for attempting to internalize positive externalities.
• Industrial Policy
• Government intervention in the economy that aims to promote technology-enhancing industries
• Patent laws are a form of technology policy that give the individual (or firm) with patent protection a property right over its invention.
• The patent is then said to internalize the externality.PRIVATE SOLUTIONS TO EXTERNALITIES
• Government action is not always needed to solve the problem of externalities.
• Moral codes and social sanctions
• Charitable organizations
• Integrating different types of businesses
• Contracting between parties
• The Coase Theorem
• The Coase Theorem is a proposition that if private parties can bargain without cost over the allocation of resources, they can solve the problem of externalities on their own.
• Transactions Costs
• Transaction costs are the costs that parties incur in the process of agreeing to and following through on a bargain.
• Why Private Solutions Do Not Always Work
• Sometimes the private solution approach fails because transaction costs can be so high that private agreement is not possible.
PUBLIC POLICY TOWARD EXTERNALITIES
• When externalities are significant and private solutions are not found, government may attempt to solve the problem through . . .
• command-and-control policies.
• market-based policies.
• Command-and-Control Policies
• Usually take the form of regulations:
• Forbid certain behaviors.
• Require certain behaviors.
• Examples:
• Requirements that all students be immunized.
• Stipulations on pollution emission levels set by the Environmental Protection Agency (EPA).
• Market-Based Policies
• Government uses taxes and subsidies to align private incentives with social efficiency.
• Pigovian taxes are taxes enacted to correct the effects of a negative externality.
• Examples of Regulation versus Pigovian Tax
• If the EPA decides it wants to reduce the amount of pollution coming from a specific plant. The EPA could…
• tell the firm to reduce its pollution by a specific amount (i.e. regulation).
• levy a tax of a given amount for each unit of pollution the firm emits (i.e. Pigovian tax).
• Market-Based Policies
• Tradable pollution permits allow the voluntary transfer of the right to pollute from one firm to another.
• A market for these permits will eventually develop.
• A firm that can reduce pollution at a low cost may prefer to sell its permit to a firm that can reduce pollution only at a high cost.
• Figure 4 The Equivalence of Pigovian Taxes and Pollution Permits
• Figure 4 The Equivalence of Pigovian Taxes and Pollution Permits
Summary
• When a transaction between a buyer and a seller directly affects a third party, the effect is called an externality.
• Negative externalities cause the socially optimal quantity in a market to be less than the equilibrium quantity.
• Positive externalities cause the socially optimal quantity in a market to be greater than the equilibrium quantity.
• Those affected by externalities can sometimes solve the problem privately.
• The Coase theorem states that if people can bargain without a cost, then they can always reach an agreement in which resources are allocated efficiently.
• When private parties cannot adequately deal with externalities, then the government steps in.
• The government can either regulate behavior or internalize the externality by using Pigovian taxes or by issuing pollution permits.