Editing Marginal cost (section)

=== Negative externalities of production ===
[[Image:NegativeExt.svg|thumb|right|Negative Externalities of Production]]

Much of the time, private and social costs do not diverge from one another, but at times social costs may be either greater or less than private costs. When the marginal social cost of production is greater than that of the private cost function, there is a [[negative externality]] of production. Productive processes that result in [[pollution]] or other environmental waste are textbook examples of production that creates negative externalities.

Such externalities are a result of firms externalizing their costs onto a third party in order to reduce their own total cost. As a result of externalizing such costs, we see that members of society who are not included in the firm will be negatively affected by such behavior of the firm. In this case, an increased cost of production in society creates a social cost curve that depicts a greater cost than the private cost curve.

In an equilibrium state, markets creating negative externalities of production will overproduce that good. As a result, the socially optimal production level would be lower than that observed.