OG10-104不理解望牛牛们知道，感觉不尽！

sasha_wen

Spending on research and development by United States businesses for 1984 showed an increase of about 8 percent over the 1983 level. This increase actually continued a downward trend evident since 1981 – when outlays for research and development increased 16.4 percent over 1980 spending. Clearly, the 25 percent tax credit enacted by Congress in 1981, which was intended to promote spending on research and development, did little or nothing to stimulate such spending.

The conclusion of the argument above cannot be true unless which of the following is true?

(A) Business spending on research and development is usually directly proportional to business profits.

(B) Business spending for research and development in 1985 could not increase by more than 8.3%.

(C) Had the 1981 tax credit been set higher than 25%, business spending for research and development after 1981 would have increased more than it did.

(D) In the absence of the 25% tax credit, business spending for research and development after 1981 would not have been substantially lower than it was.(D)

(E) Tax credits market for specific investments are rarely effective in inducing businesses to make those investments.

OG：Since a tax credit generally improves business profits, if the conclusion is true choice A is
unlikely to be true. If the tax credit was ineffective, some other factors must determine the level
of spending, and could lead to much higher levels of spending in 1985 (against choice B), and
could render a higher level of tax credit ineffective (against choice C), but it could be that
credits are generally effective (against choice E).

里对B的解释不理解，望牛牛们指导

sdcar2010

B) Business spending for research and development in 1985 could not increase by more than 8.3%

If so, then spending on R&D in 1985 has been stimulated to its upper limit (in other words, R&D spending has reached its ceiling).  This is countrary to the conclusion of the argument that the tax credit did nothing to stimulate R&D spending.

sasha_wen

我的理解1985增长不超过8.3%但可以是8.2%，还是高于1984年的，那the 25 percent tax credit 有用的，所以countrary to the conclusion ，但是要是1985增长不超过8.3%假定7%，那低于1984年，不就成了the 25 percent tax credit无用，求牛牛们知道

sdcar2010

This is a necessary assumption question.  You can use the negation method.

When you negate D, you get - In the absence of the 25% tax credit, business spending for research and development after 1981 would have been substantially lower than it was.  If this is true, the arugment falls apart, since it means that the tax credit DOES stimulate R&D spending.  So D is the necessary assumption.

All the other answer choices, if negated, would not revoke the argument.  Hence, they are not the necessary assumption.

sdcar2010

In 1985, if the increase in R&D spending is 7%, that does not mean the tax credit has no effect because without the tax credit, the increase would have been even lower than 7%.

erlyl

sdcar2010 发表于 2010-12-22 01:10
This is a necessary assumption question.  You can use the negation method.When you negate D, yo ...

我想问问E是怎么样呢？
税很难对引导有效
取非：很容易有效
有效了就对conclusion的几乎无效 反驳了呀。

sdcar2010

erlyl 发表于 2016-9-9 15:59
我想问问E是怎么样呢？
税很难对引导有效
取非：很容易有效

E is irrelevant to spending in R&D. Note the shift from spending in R&D to inducing businesses to make specific investments.