假定供给与需求状况与习题3中描述的一样，但生产不能带来边际社会收益。然而，由于某些政治原因，该国政府认为

价值1美元的生产者所得相当于2美元的消费者所得或政府收益。试计算对每单位进口产品征收5个单位的关税给政府目标带来的影响。

Suppose that demand and supply are exactly as described in problem 3 but there is no marginal social benefit to production．However，for political reasons the government counts a dollar's worth of gain to producers as being worth ＄2 of either consumer gain or government revenue．Calculate the effects on the government's objective of tariff of 5 per unit．