弱弱地说明一下，这个题感觉应该很简单，但真的困住妹子一个晚上了，求解答啊！！！！！！谢谢好心人！

克鲁格曼《国际经济学》国际贸易理论第8章课后习题第6题啊！！！！

原题是对于小麦有：本国D=100-20p, S=20+20p; 外国D*=80-20p, S*=40+20p; 两国间贸易无运输成本。现在外国对于每单位产品出口给予0.5的补贴。要求1、小麦价格，2、对两国各社会集团的影响，3、整个社会福利的影响。

不懂之处在于，对于外国的各社会集团的影响怎么解？
我找到了答案，答案说是消费者损失7.5，生产者增加15.3，ZF损失19.2，外国的总损失为19.2+7.5-15.3=11.4。

冥思苦想也不知此处的外国消费者损失和生产者增加怎么算来的，求解答。

附：找到的此题答案如下：


We first use the foreign export supply and domestic import demand curves to determine the new world price. The foreign supply of exports curve, with a foreign subsidy of 50 percent per unit, becomes XS *= - 40+40(1 +0.5) * P. The equilibrium world price is 1.2 and the internal foreign price is 1.8. The volume of trade is 32. The foreign demand and supply curves are used to determine the costs and benefits of the subsidy. Construct a diagram similar to that in the text and calculate the area of the various polygons. The government must provide (1.8 - 1.2)*32=19.2 units of output to support the subsidy. Foreign producers surplus rises due to the subsidy by the amount of 15.3 units of output. Foreign consumers surplus falls due to the higher price by 7.5 units of the good. Thus, the net loss to Foreign due to the subsidy is 7.5 + 19.2 - 15.3 = 11.4 units of output. Home consumers and producers face an internal price of 1.2 as a result of the subsidy. Home consumers surplus rises by 70* 0.3+ 0.5 (6 * 0.3) = 21.9, while Home producers surplus falls by 44 * 0.3 + 0.5(6 * 0.3) = 14.1, for a net gain of 7.8 units of output.


谢谢谢谢！！！！！！