In economics, externalities are costs or benefits that impact individuals who are not directly involved in a transaction. Picture a factory emitting smoke that affects the health of people living nearby. Those residents incur costs, like medical bills, even though they were not part of any agreement with the factory.
This concept is critical because externalities are not accounted for in the usual market processes. They can lead to outcomes that are not socially optimal—for instance, too much pollution or too little production of socially beneficial goods.
There are two types of externalities:
- **Negative externalities**: These impose costs on others, such as pollution, noise, or congestion.
- **Positive externalities**: These provide benefits, such as the planting of trees that improve air quality or education that increases a community's overall knowledge base.
When externalities exist, markets may fail to allocate resources efficiently on their own. That's where interventions or negotiated solutions may come into play, often relying heavily on the principles of property rights and bargaining laws.