Question

英文的微观经济学作业，请高手解答一下，中英文都可！谢谢

Exercise 2
The demand for automobiles in a certain country is given by
D = 12,000 – 200P
where P is the price of a car. Supply by domestic automobile producers is
S = 7,000+ 50 P.
a)Assuming that the economy is closed, find the equilibrium price and production of automobiles
b) The economy opens to trade. The world price of automobiles is 18. Find the
domestic quantities demanded and supplied and the quantity of imports or exports.
Who wil1 favour the opening of the automobile market to trade, and who will oppose it?
c) The government imposes a tariff of 1 unit per car. Find the effects on domestic 'quantities demanded
and supplied and on the quantity of import or export. Also find the revenue raised by the tariff. Who
wil1 favour the imposition of the tariff, and who wil1 oppose it?

Answer 1

a) D = S
so 12000–200P = 7000+ 50P
so P = 20
无贸易条件下，均衡价格为20

b) The world price of automobiles is 18.
so P = 18
so domestic quantities demanded = 12000-200*18 = 8400
domestic quantities supplied = 7000+50*18 = 7900
即：贸易条件下，国内需求为8400，国内供给为7900
显然，供小于求，应该进口
so quantity of imports = 8400-7900 = 500
显然，消费者剩余增加了，国内生产者剩余减少了，而国外生产者也当然乐于进入该国市场
so the consumer and the foreign supplier will favour it and the domestic supplier will oppose it

c) a tariff of 1 unit per car.
so P = 18+1 = 19
so domestic quantities demanded = 12000-200*19 = 8200
domestic quantities supplied = 7000+50*19 = 7950
so quantity of imports = 8200-7950 = 250
显然，价格升高导致进口减少了，消费者剩余减少了，国内生产者的生产者剩余增加了，国外生产者的生产者剩余减少，政府由于收取关税，其收入增加
谁赞成谁反对，一目了然。