求助Prep07 CR2 50题（assumption）

instinctwu

50.     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.

这类题应该怎么做啊？我assumption题型老是不对。

tofreesky

注意题目问的是循环：税率提高——交税的人面临更高的税金——更多的人逃税——税率再次提高。。。从以上逻辑链条中可以看出，需要对更多的人逃税——税率再次提高这个逻辑链条加强。这样需要加强的主体就是lawmaker，答案和lawmaker有关C如果是真的，那么这个逻辑链条就存在，如果不是真的，那由于lawmaker 意识到这一点就会改变措施，就不存在税率再次提高这种情况存在。
我认为，assumption的题型最主要的是对逻辑链条的加强以及对于使结论存在条件的加强。

instinctwu

谢谢。C项的意思是不是说lawmaker在提高税率的同时也能够防止逃税行为的发生？我怕我理解歪了。选项中用了allow for，意思是“不考虑”，那如果lawmaker没有考虑税收的遗漏的问题，那人们还是会继续evade income tax啊，这样的话这个恶性循环还是不会结束。如果是我理解错了请指出，哈哈。

tofreesky

不是，C表明的是lawmaker政策选择性的问题。如果如选项所说，没有考虑到税收遗漏的问题，那么该政策会继续实施，人们就继续逃税，从而对于结论的成立条件之一作了界定。如果lawmaker考虑到了税收遗漏的问题，那么就会取消这种政策。后面的情况就不会再发生，就是对原来这种循环存在的结论进行了削弱。
C选项没有表明在提高税率的同时也能够防止逃税行为的发生这层意思。

liuyinghong

解释的好清楚