Externalities
Externalities
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. If the impact on the bystander is adverse, it is called a negative externality; if it is beneficial, it is called a positive externality.
In the presence of externalities, society’s interest in a market outcome extends beyond the well-being of buyers and sellers in the market; it also includes the well-being of bystanders who are affected. Because buyers and sellers neglect the external effects of their actions when deciding how much to demand or supply, the market equilibrium is not efficient when there are externalities. That is, the equilibrium fails to maximize the total benefit to society as a whole. The release of dioxin into the environment, for instance, is a negative externality. Self-interested paper firms will not consider the full cost of the pollution they create and, therefore, will emit too much pollution unless the government prevents or discourages them from doing so.
Externalities come in many varieties, as do the policy responses that try to deal with the market failure. Here are some examples:
a. The exhaust from automobiles is a negative externality because it creates smog that other people have to breathe. As a result of this externality, drivers tend to pollute too much. The federal government attempts to solve this problem by setting emission standards for cars. It also taxes gasoline to reduce the amount that people drive.
b. Restored historic buildings convey a positive externality because people who walk or ride by them can enjoy their beauty and the sense of history that these buildings provide. Building owners do not get the full benefit of restoration and, therefore, tend to discard older buildings too quickly. Many local governments respond to this problem by regulating the destruction of historic buildings and by providing tax breaks to
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. If the impact on the bystander is adverse, it is called a negative externality; if it is beneficial, it is called a positive externality.
In the presence of externalities, society’s interest in a market outcome extends beyond the well-being of buyers and sellers in the market; it also includes the well-being of bystanders who are affected. Because buyers and sellers neglect the external effects of their actions when deciding how much to demand or supply, the market equilibrium is not efficient when there are externalities. That is, the equilibrium fails to maximize the total benefit to society as a whole. The release of dioxin into the environment, for instance, is a negative externality. Self-interested paper firms will not consider the full cost of the pollution they create and, therefore, will emit too much pollution unless the government prevents or discourages them from doing so.
Externalities come in many varieties, as do the policy responses that try to deal with the market failure. Here are some examples:
a. The exhaust from automobiles is a negative externality because it creates smog that other people have to breathe. As a result of this externality, drivers tend to pollute too much. The federal government attempts to solve this problem by setting emission standards for cars. It also taxes gasoline to reduce the amount that people drive.
b. Restored historic buildings convey a positive externality because people who walk or ride by them can enjoy their beauty and the sense of history that these buildings provide. Building owners do not get the full benefit of restoration and, therefore, tend to discard older buildings too quickly. Many local governments respond to this problem by regulating the destruction of historic buildings and by providing tax breaks to