Maximizing the Net Benefits of Pollution

Read this section about how to apply the Coase Theorem to solve environmental problems.

2. Pollution and Scarcity

Pollution exists whenever human activity generates a sufficient concentration of a substance in the environment to cause harm to people or to resources valued by people. Many potentially harmful substances are natural features of the environment, but they are not generally regarded as pollutants. Pollution is the product of people, not nature.

Pollution implies scarcity. If an activity emits harmful by-products into the environment, then the emission of the by-products is an alternative to some other activity. A scarcity problem exists at the point where harm occurs. A fire burning in a fireplace at a cabin in the forest whose smoke goes unnoticed does not suggest a scarcity problem. But when there are other people who will be harmed by the smoke, then one person's enjoyment of the fire becomes an alternative to another person's enjoyment of fresh air. Fresh air has become scarce, and pollution has become an economic problem.

Economists generally argue that pollution that harms plants or animals imposes a cost if the plants or animals are valued by people. When a farmer uses a pesticide that damages another farmer's crop, for example, a pollution problem occurs. If an oil spill in the ocean damages sea animals that people care about, there is a pollution problem. It is, after all, people who make the choices that lead to pollution. It is people who can choose to limit their pollution. Economists therefore examine pollution problems from the perspective of the preferences of people.