Which of the following statements are true regarding​ externalities? ​(Check all that apply​.) A. Deadweight loss can be either a foregone benefit or the total cost of the externality to society. B. In the case of an​ externality, the free market will maximize social surplus. C. For computing efficient​ outcomes, economic agents adjust the demand curve to account for negative externalities. D. A negative externality occurs when an economic activity has a spillover cost to a bystander.

d

Explanation:

A good has positive externality if the benefits to third parties not involved in production is greater than the cost. an example of an activity that generates positive externality is research and development. Due to the high cost of R & D, they are usually under-produced. Government can encourage the production of activities that generate positive externality by granting subsidies.

A good has negative externality if the costs to third parties not involved in production is greater than the benefits. an example of an activity that generates negative externality is pollution. Pollution can be generated at little or no cost, so they are usually overproduced. Government can discourage the production of activities that generate negative externality by taxation. Taxation increases the cost of production and therefore discourages overproduction. Tax levied on externality is known as Pigouvian tax.

Government can regulate the amount of externality produced by placing an upper limit on the amount of negative externality permissible

Coase theorem has been proposed as a solution to externality. According to this theory, when there are conflicting property rights, bargaining between parties involved can lead to an efficient outcome only if the bargaining cost is low

Another solution to negative externality is through the activities of charities. Charities can raise donations to limit or regulate the activities of firms that constitutes a negative externality.