The external costs of alcohol consumption are related to, among other things, death and injury related to auto accidents caused by drunk drivers. These costs have been estimated to be about 47 cents per ounce of alcohol consumed. Taxes on alcohol amount to 23 cents per ounce. This suggests that alcohol consumption is (i) greater than the efficient or optimal amount; (ii) should be reduced to zero to eliminate the externality.

A demand curve

A) has an upward slope. B) has a downward slope. C) is a graph of the relationship between quantity demanded of a good and its price. D) Both answers B and C are correct. E) Both answers A and C are correct.

Marginal private cost

A) is always zero if there is an external cost. B) equals the marginal social cost only if the marginal external cost is positive. C) is the cost of producing an additional unit of a good or service that is paid by the producer of that good or service. D) the cost of producing an additional unit of a good or service that falls on people other than the producer of that good or service. E) the cost of producing an additional unit of a good or service that is paid by the entire society.