T-9-Q4
    A
   D

In the years following an eight-cent
increase in the federal tax on a pack of cigarettes, sales of cigarettes fell
ten percent. In contrast, in the year prior to the tax increase, sales had
fallen one percent. The volume of cigarette sales is therefore strongly related
to the after-tax price of a pack of cigarettes.

The argument above requires which of
the following assumptions?

A.     
During the year following the tax increase, the pretax
price of a pack of cigarettes did not increase by as much as it had during the
year prior to the tax increase.

B.     
The one percent fall in cigarette sales in the year prior
to tax increases was due to a smaller tax increase.

C.     
The pretax price of a pack of cigarettes gradually
decreased throughout the year before and the year after the tax increase.

D.      For the year following the tax increase, the pretax price
of a pack of cigarettes was not eight or more cents lower than it had been the
previous year.

E.      
As the after-tax price of a pack of cigarettes rises, the
pretax price also rises.

没思路啊！ 那位大牛给我解释一下啊，谢谢！

我怎么感觉换成“was not 8 or more cents(percents?)higher”作为排除他因比较好啊？说明税后价格高不是因为加税，而是税前价格上升了？

继续请教

我懂了

属于同因异果型削弱

若税前价格比前年降低了>=8cents的话，那么D选项就造成了一种类比；即那么同样的情况，不同的结果——sales只下降1%，而非10%；
            这样就使推论毫无意义

1.       T-9-Q4.
            

In the years following an eight-cent increase in the federal tax on a pack of cigarettes, sales of cigarettes fell ten percent. In contrast, in the year prior to the tax increase, sales had fallen one percent. The volume of cigarette sales is therefore strongly related to the after-tax price of a pack of cigarettes.

每包香烟的税增加8分的哪一年，销售量下滑10％。

在增税之前的那一年，销售量下滑了1％。

à
        香烟的销售量和每包香烟的税后价格高度相关。

（基本假设：增加的这8分，会让今年的税后价格较去年高）

The argument above requires which of the following assumptions?

1. During the year following the tax increase, the pretax price of a pack of cigarettes did not increase by as much as it had during the year prior to the tax increase.
                   （前一年的税前价格增加较多，今年的税前价格增加较少，则不知增加8分的税后价格是增加还是减少，因此不能做成本论之结论）

2. The one percent fall in cigarette sales in the year prior to tax increases was due to a smaller tax increase.（支持结论，而非结论之基本假设）

3. The pretax price of a pack of cigarettes gradually decreased throughout the year before and the year after the tax increase.（税前价格逐年降低，则不知税后的价格是增加还是减少，因此不能做成本论之结论）

4. For the year following the tax increase, the pretax price of a pack of cigarettes was not eight or more cents lower than it had been the previous year.（如果在增加8分之前的税前价格就比原来的税前价格低了八分或更低，则即使增税八分，税后价格还是比较低，所以要排除这个就是这个因果关系的基本假设）

5. As the after-tax price of a pack of cigarettes rises, the pretax price also rises.（税后价格增加，税前价格也同时增加，无法确定这个增加是由税所引起的，还是由原本的价格所引起的，所以无法确定税收影响销售额之因果关系。）

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