帮忙看一下~prep2-50

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.

 答案选的是C，请问A为什么不对呢？

A）至少不会直接导致恶性循坏而出现更多逃税的人。如果这些纳税人因为税率高而更努力工作从而赚到更多税前工资，他们并没有必要逃税。举个身边的例子，房价的高企只会让我们这些人更努力工作，而动坏脑筋比如去抢银行的绝对是少数中的少数，毕竟要杀头的。

C）则会有很明显的导致恶性循坏的趋向。基本上已经逃税的不会回到缴税的队列中来，因此他们该缴全部被分摊到其他的良民纳税者头上。这样会导致只可能出现越来越多的逃税者，而越来越多的逃税者会导致纳税者的分摊越来越大，如是则形成恶性循坏。