Answer:
Because the government can use her sovereign power to both mitigate negative externalities as well as encourage positive externalities.
Explanation:
A positive externality occurs when the transaction between a producer and end user benefits a third party that did not take art in the process.
A very Good example is Education. There is a third party benefit to the society when we have more educated citizens.
A negative externality happens when the business transaction between a manufacturer and consumer affects a third party adversely. a typical example is cigarettes. When cigarettes is consumed by the end user, the smoke can affect the health of a third party that was not part of the initial transaction.
To deal with both positive and negative externalities, government intervention is very crucial.
Government encourages positive externalities like education by subsidizing the cost of attending a school. They also enact laws that make basic education compulsory.
In the case of negative externalities, Government can intervene with a ban on producing harmful goods and also set a legislation about smoking in public laces to mitigate the health complications caused by third party inhalation.
