国际顶尖MBA申请交流平台--TOPWAY MBA

The country of Maravia has severe air pollution, 80 percent of which is caused by the exhaust fumes of cars. In order to reduce the number of cars on the road, the government is raising taxes on the cost of buying and running a car by 20 percent. This tax increase, therefore, will significantly reduce air pollution in Maravia.

Which of the following, if true, most seriously weakens the argument above?

(A) The government of Maravia is in the process of building a significant number of roadways.

(B) Maravia is an oil-producing country and is able to refine an amount of gasoline sufficient for the needs of its population.

(D) Ninety percent of the population of Maravia is very prosperous and has a substantial amount of disposable income.（D）

(E) In Maravia, cars that emit relatively low levels of pollutants cost 10 percent less to operate, on average, than do cars that emit high levels of pollutants.

这题我认为应该选E,D是一个无关选项。

加税意味着汽车更贵了，价格上升导致需求下降，所以汽车交易量减少了，污染也就少了。>>

D选项说M国人很有钱，这跟汽车需求变化没有任何关系。也许一个有钱人不在乎价格贵了20%，继续购买汽车。但是整个国家作为一个统计整体一定会对汽车价格上升作出反应。

E说低污染汽车本来就便宜，那么就是说除了价格因素还有其他因素促使高污染汽车的销售，也就是加税提高价格不一定能导致污染减少，构成了它因削弱。

D says that ninety percent of the population of Maravia is very prosperous and has a substantial amount of disposable income.

a substantial amount of disposable income 说明有钱到上涨20%对大部分人来说影响很小，所以削弱

是这样的，就算整个国家的人都很有钱，买个汽车对该国人来说就跟我们买个玩具汽车一样，可是就算玩具汽车的销量也跟价格相关呀！涨了价玩具汽车销售量也会下跌。所以汽车销售量应该跟价格相关，而跟消费者富足程度无关。

以下是引用pianer在2009-12-30 7:00:00的发言：
这题我又想了一下，E也不对。原题只说污染和汽车尾气排放有关，没提过排污量大的车和排污量小的车，E也是无关选项。
我想D的本意是说汽车这种产品的需求曲线弹性很差，所以销售量跟价格关系不大，构成削弱。但是产品需求曲线弹性跟消费者是否富足是没有关系的。照D的意思，由于M国国民富足，在M国任何商品价格上涨都不会对销售量构成很大影响，这不是很荒谬吗？
此题的出题者可能不懂经济学，这题出的不好，不去管他了。

经济学上对商品的分类其中有一种是奢侈品, 而奢侈品存在且有市场的前提是富裕消费者的存在.