申論題

2. Suppose the demand curve of a specifc kind of fower for Country A is Q^D = 200 - P, where Q^D is the quantity demanded and P is the price. The supply curve in the same market is Q^s = 3P, where Q^s is the quantity supplied.

(A) (15 points) Suppose scientists fnd that the scent of this specific kind of follower can cure mental disorders. Hence, for each unit of the quantity demanded brings $80 external benefit. Assume the world price pw is $60 and is not affected I by Country A's policies. Considering this external beneft, should Country A export or import how many units of this good? Please draw a graph and label all relevant points. Also, please show your calculation.