CR - Hybrid Cars

[cpkelley5]

I need some help understanding the rationale behind correct answer on this question:

Congress has passed a law that scales back the tax credits offered to purchasers of hybrid cars. Because of this, the number of hybrid cars sold each year, which has approximately doubled in each of the last five years, is likely to flatten in the next few years.

Which of the following statements, if true, most weakens the conclusion that the number of hybrid cars sold annually is likely to flatten in the next few years?

A) Most people buy hybrid cars for reasons other than to save money in the long run.

B) Recently published studies have shown that hybrid cars cost significantly more to repair and maintain than do comparable traditional cars.

C) Gasoline prices are projected to fall over the next few years.

D) Hybrid vehicles have a reputation for having less power than comparable non-hybrid vehicles.

E) Manufacturers have significantly increased their budgets for advertisements touting the fuel efficiency of hybrid cars.

It's my understanding that in order to weaken the conclusion (that sales will flatten), we need to find an assumption that shows that there's a chance for the sales to continue to rise.

The correct answer is A. The question implies that since there will be no monetary incentive to purchase the car, sales will flatten. These incentives originally were only given to purchasers of hybrid cars and not a on a long term basis to the actual owners. This answer choice implies that the original purchasers were ones interested in long-term incentives, which the tax credit is not. If it said "to save money." or "to save money in the short term." then yes I can see how it's correct.

On the other hand, I don't understand how E can be incorrect. Advertising is there to drive sales. If the budget increases, is it not safe to assume that advertising will increase and that there's a positive correlation between advertising and sales?

Pleases shed light where possible. This question seems wishy-washy and I'm getting frustrated. Thanks!

[jnelson0612]

Please see this thread, which explains why A is correct: congress-has-passed-a-law-that-scales-back-the-tax-credits-t11006.html

[jnelson0612]

On the other hand, I don't understand how E can be incorrect. Advertising is there to drive sales. If the budget increases, is it not safe to assume that advertising will increase and that there's a positive correlation between advertising and sales?

Pleases shed light where possible. This question seems wishy-washy and I'm getting frustrated. Thanks!

As for E, I can understand where you are coming from, but it's a little out of scope of the argument. To weaken the argument, let's attack the assumption. The assumption is the necessary bridge between the premises and conclusion.

Conclusion: Number of hybrid cars sold is likely to flatten in the next few years.
Why? Because:
Premise: Tax credits given to hybrid purchasers have been scaled back.

To help me get from that premise to that conclusion, I MUST assume that the tax credits have an influence on whether people choose to buy hybrids. If the tax credits have no influence on whether people buy hybrids, the conclusion does not stand. Notice how this concept is the correct weaken answer.

Your answer is outside the scope of the idea that the tax credits (money) influence whether people buy. A is superior to E because it is actually in the scope of the argument and directly attacks the assumption.

I hope that this helps!

[cpkelley5]

Awesome. Great explanation Jamie. That helps a lot.

[jnelson0612]

Great to hear, thanks! :-)