122.

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 years 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.

122.

For tax evasion to force a raise in income tax rates it must be true that tax evasion causes actual tax revenues to fall short of revenue needs. This is the situation that choice C describes; choice C is therefore the best answer.

None of the other choices states a requirement for the vicious cycle to result. Increasing in pretax incomes (income A) would tend to work against perpetuation of the cycle. Success at catching tax evaders (choice B) should likewise have an inhibiting effect. Choice D describes how problems in breaking existing habits of tax evasion might be overcome. Choice E essentially denies that raising the tax rate in response to some tax evasion could cause additional tax-payers to evade taxes.

原题能看明白可就是不明白为什么选择D？ 请大牛详细分析一下D与题纲的关系

谢谢

C是答案啊.

这题我也想了半天，后来发现是对题干理解的问题：

A not true unless B true,就是说B发生的情况下，A发生（与A not true相反）

e.g."My baby sister never cries unless she is hungry."

所以这题的题干的意思是：在以下何种情况成立的条件下，该vicious cycle会发生？

C的意思是“那些lawmaker在制定提高税率来提高收入的政策时，没有充分考虑到该政策会导致的收入下降”，在这种情况下，是会发生题目中说的vicious cycle的。

其他选项则会导致vicious cycle不发生，所以不正确。

说明法律制定者没考虑漏税的因素，所以，每次提高税率以达到原先预想的财政收入都不可能完成，还造成了更多人漏税，但是，法律制定者为达预计的目的，在仍然没考虑漏税因素情况下，又提高税率，造成了循环。因此，法律制定者没考虑漏税情况是这个循环成立的关键。