真题三套中的逻辑题（test 3， 15），请教

snow18

When people evade income taxes by not declaring taxable income, a vicious cycle results. Tax evasion forces lawmakers to raise income tax rates, which causes the tax burden on nonevading taxpayers to become heavier. This, in turn, encourages even more taxpayers to evade income taxes by hiding taxable income.  
The vicious cycle described above could not result unless which of the following were true?  
(A) An increase in tax rates tends to function as an incentive for taxpayers to try to increase their pretax incomes.  
(B) Some methods for detecting tax evaders, and thus recovering some tax revenue lost through evasion, bring in more than they cost, but their success rate varies from year to year.  
(C) When lawmakers establish income tax rates in order to generate a certain level of revenue, they do not allow adequately for revenue that will be lost through evasion.  
(D) No one who routinely hides some taxable income can be induced by a lowering of tax rates to stop hiding such income unless fines for evaders are raised at the same time.  
(E) Taxpayers do not differ from each other with respect to the rate of taxation that will cause them to evade taxes.  
答案是c，这道题相当于文前提吧？。。。不成立，除非。。。
为什么是c???
谁来解答一下  ，
抱拳谢过！！！

kathy72

文章的推导过程:
逃税 --> 政府税收不足 --> 提高税率-->更多人逃税

将C取非, 如果政府在制定税收政策时已经考虑到逃税的情况(例如将税率已适当提高以保证有人逃税时仍税源充足), 那么有人逃税不一定会导致税收不足而使税率提高. 削弱了原文结论.因此是假设.

travellogue

This question is confusing. In the beginning, I thought E is the answer. A, B, and D are easily ruled out. A or B is irrelevant to the logic in questions. D is talking about lowering tax rate.  E actually is a weakening. Because taxpayer is indiffernt to the level of rate, increase in tax would have no impact on the taxpayer's behavior. Hence, the number of tax evader would remain the same.

八戒

E actually is a weakening. Because taxpayer is indiffernt to the level of rate, increase in tax would have no impact on the taxpayer's behavior. Hence, the number of tax evader would remain the same.

I have a different view.

The contrary of E may support the argument,depending on how you understand the meaning of E.
In the light of yours, I admit that taxpayer is indiffernt(this word is puzzling,its meaning is "do not care of ", not equal to same.Maybe you want to say :taxpayer differ from each other with respect to the rate of taxation.If so ,we can continue discussing.If not , we go another way ) to the level of rate.As far as I am concerned, I grab this meaning that different taxpayer will evade the income tax due to  the different level of the income tax.

For example, if your income is $1000,you may evade the income tax when that tax is 5%.But if your income is $2000,you may evade the income tax when that tax is 10%.

So, I think the contradictory of E support the argument.
C is the best choice.

Appreicate any comments.

dandan74

我赞同八戒的说法，E这个选项是典型的干扰选项，仔细想想好象ETS有很多的题都有个类似的选项。这种选项往往说的很含糊，给你以想象的空间，你就会自然上套了，如kathy地分析，紧紧扣住原文的line of reasoning，才能排除其他的干扰。
就E这个选项本身，taxpayers虽然在不同的税率情况下evade税的可能性不同，不能推出increase in tax would have no impact on the taxpayer's behavior. travellodge所说的这个结论，准确地说，这不是一个结论，而是speculation.