#14 - Charles: During recessions unemployment typically rise

[Administrator]

Complete Question Explanation

Assumption-CE. The correct answer choice is (D)

This question asks you to identify a necessary assumption in Charles' argument. Since you know that Charles ignores additional factors, you should focus on that when you review the choices.

Answer choice (A): If people who have never been employed keep up their driving levels during a recession, that does not help prove that fewer cars would be on the road, or that pollution would decrease, so this unhelpful response can be quickly eliminated.

Answer choice (B): Since Charles does not argue that overall air pollution would decrease, and restricts himself to pollution caused by automobiles, a response about the relative amount of pollution that automobiles contribute is irrelevant to his argument, so this choice is wrong.

Answer choice (C): The effect of this choice upon the argument is unclear. If most people employed do not use public transportation, that makes it more likely that recessions would affect drivers. However, if most of the people employed did use public transportation, it could still be true that a large number of those employed drive, so recessions could still affect drivers. This choice fails the negation test, and is incorrect. As a point of clarification, Charles does need to assume that some of those employed sometimes do not use public transportation, but that assumption does not need to be any more extreme.

Answer choice (D): This is the correct answer choice. Charles needs to assume that additional factors do not counter the possibility that fewer people need to drive to work. If the reduction in driving to work were offset by an increase in driving for other reasons, Charles' conclusion would not follow, so it is critical that Charles assume there is no countering increase of automobile use for other reasons.

Answer choice (E): Charles does not need to assume that more people who drive than people who do not drive lose their jobs during a recession. As long as some people who drive lose their jobs, the recession could have the effect he proposes on drivers, even if most people were not driving, so this choice is wrong.

[rachue]

Hi, I got this one correct but I'm still trying to understand why A is completely wrong.

I understood the stimulus to mean that during a recession, people who had jobs drive less bc of lack of job, and therefore there is less air pollution.

For the recession to be the indirect cause of less air pollution, doesn't this assume that everything else had to have remained constant? What if other drivers were driving less? Isn't A just saying that another factor, other drivers who weren't affected by the recession, drove the same amount, therefore keeping the other main factor constant and allowing Charles' argument to be properly drawn?

I think I need some clarification...what am I missing here?

[Steve Stein]

Charles' conclusion that air pollution drops along with employment rates does not require that everything else remain constant, since a given effect can have more than one contributing cause. Thus, Charles' argument does not rely on the assumption provided by Answer choice A (as a side note, Answer choice A deals with people who have never been employed, whereas Charles' argument appears to deal with the newly unemployed, who emerge as a result of economic recession).

[rachue]

Ok, that helps. Thanks!

[GLMDYP]

Hi Powerscore!
I chose the answer choice (C), which I think is appropriate. Since most people who are employed use only private cars to go to work, thus when fewer people commute in cars to jobs, there will be fewer emissions into the air.
How does (D) come to work? How can there be "increased use of cars for other reasons" during a recession?
Thanks!

[Ron Gore]

Thank you for your question, GLMDYP.

Remember that your task in an assumption question is to select the answer choice logically required for the conclusion to have even a chance at being valid. The choices in this type of question each will contain new information to be added to conclusion and analyzed as to their relationship to the conclusion.

This question is an example of a Defender type assumption question, in which the correct answer raises a potential attack on a flaw in the argument, and then defends the conclusion against that attack by dismissing the possibility. Here, a logical flaw in Charles' argument is that he assumes that just because people aren't commuting to their former jobs in cars, that they aren't using their cars for other purposes. While it's not important to answering this question do know what those alternate uses are, you could imagine they might be things like going back to school, or attending job interviews, etc.

Answer (D) is the correct answer, because it raises the possible attack that they might be using their cars for other purposes, and then dismisses that possibility by adding the word "not": During a recession, decreases in the use of cars resulting from reductions in commuting to jobs are NOT offset by increased use of cars for other reasons." We can confirm that the information in this choice is required for the conclusion to be valid, because if we logically negate the choice by removing the word "not," the choice attacks the conclusion. We refer to this confirmation process as the Assumption Negation Technique. Notice that, unlike choice (C), this choice does not leave ambiguous the question of numbers, i.e., what percentage of folks were driving to work, what percentage were using other transportation methods. The idea of "offset" in this choice tells us that regardless of the numbers, the effect is not offset.

We cannot say that (C) is required for the conclusion, because it is not required that "most" people who are employed not use any form of public transportation to commute to work. The argument, which spoke of "fewer people" using cars "less" does not require that 51% or more of those employed, i.e., "most", not use any mode of public transportation. You can see this by applying the Assumption Negation Technique, the result of doing so will not attack the conclusion: "It is not the case that most people who are employed do not us any form of public transportation to commute to their jobs." Even if you are not convinced by the numbers idea above, their is no reason to assume that their are only two possible transportation alternatives for people, either car or public transportation. Doing so ignores the possibility of walking and riding a bicycle, for example.

Hope that helps.

Ron

[ellenb]

Dear Powerscore,

For this question I picked B and the correct answer choice is D. I just want to know why B is wrong and D is right. Is it because in D we are making sure that the cars are not used for other reasons than going to jobs? We are sort of making sure that no other uses of the cars happen?

Thanks
Ellen

[David Boyle]

Dear Powerscore,

For this question I picked B and the correct answer choice is D. I just want to know why B is wrong and D is right. Is it because in D we are making sure that the cars are not used for other reasons than going to jobs? We are sort of making sure that no other uses of the cars happen?

Thanks
Ellen

Hello Ellen,

Charles and Darla again, huh? --O.K., B, "Most air pollution is caused by automobile exhaust emitted by cars used by people commuting to jobs", is an unwarranted, unnecessary assumption, even if it maybe helps Charles' point. In D, though, "During a recession, decreases in the use of cars resulting from reductions in commuting to jobs are not offset by increased use of cars for other reasons" is necessary because Charles says that cars' decreased pollution is the big factor. If for whatever other reason, cars are actually used more, and pollution is increased, that knocks Charles' argument to pieces.
It's not exactly like you said above, that "cars are not used for other reasons than going to jobs . . . no other uses of the cars happen", since that is a little extreme. People will presumably always use cars for *some* other purposes than jobs, but how much they use them (including during a recession) is another issue.
Hope that helps,

David

[ellenb]

So, if I negate answer choice D, it would be "decreases in the use of cars resulting from reductions in the commuting to jobs are offset by increased use of cars for other reasons"
which basically says that pollution decreases even though people use the cars for other reasons than commuting to jobs. Which would make the conclusion false, because it assumes that most of the pollution happens because people drive to jobs. So, if we say that people use their cars for other reasons than commuting to their jobs than the conclusion falls. Did I get it right?
I feel still a bit confused with it.

Did I negate it correctly? And how is answer choice B an unwarranted assumption?

Thanks
Ellen

[David Boyle]

So, if I negate answer choice D, it would be "decreases in the use of cars resulting from reductions in the commuting to jobs are offset by increased use of cars for other reasons"
which basically says that pollution decreases even though people use the cars for other reasons than commuting to jobs. Which would make the conclusion false, because it assumes that most of the pollution happens because people drive to jobs. So, if we say that people use their cars for other reasons than commuting to their jobs than the conclusion falls. Did I get it right?
I feel still a bit confused with it.

Did I negate it correctly? And how is answer choice B an unwarranted assumption?

Thanks
Ellen

Hello,

As for B, how do you know that ***most*** "air pollution is caused by automobile exhaust emitted by cars used by people commuting to jobs"? What evidence is there for that?
As for your negation of answer choice D, yes, it does attack the conclusion. That's the point of the assumption negation technique; if the negation attacks the conclusion, that shows that the assumption, in its normal, non-negated form, "strengthens" (is a necessary premise on the way to) the conclusion.
(By the way, you said that in the negated form, it shows pollution decreases. No, rather, it may increase, because of the "increased use of cars for other reasons" which causes more pollution. Also, you said "the conclusion . . . assumes that most of the pollution happens because people drive to jobs." No, it does not assume that **most** of the pollution results from that.)

David