Externalities

In economics, an externality is a cost or benefit to an uninvolved third party that arises as an effect of another party's activity. Externalities can be considered as unpriced components that are involved in either consumer or producer consumption. Air pollution from motor vehicles is one example. The cost of air pollution to society is not paid by either the producers or users of motorized transport. Water pollution from mills and factories are another example. All (water) consumers are made worse off by pollution but are not compensated by the market for this damage. Read more on Wikipedia