Scott: In our towns upcoming election, the mayor is running for

Official Explanation:

Scott: In our town’s upcoming election, the mayor is running for re-election against an opponent whose popularity is currently greater than the mayor’s because of the opponent’s support for a plan that would forbid national chain stores in the downtown area. The mayor and his party should take note of this and pledge to support limiting such stores downtown.

The argument above relies on which of the following assumptions?

A. The mayor, by announcing a limit on national chain stores downtown, would increase voter turnout in the upcoming election.
B. Some voters who plan to support the mayor’s opponent would not do so if the mayor limits national chain stores downtown.
C. The mayor has the authority to limit the opening of national chain stores downtown.
D. The plan to forbid national chain stores downtown is supported by a majority of the town’s residents.
E. Most voters who currently plan to vote for the mayor’s opponent do not currently know of the mayor’s position on this issue.

Question Type: Assumption
Boil It Down: Because the opponent is more popular than the mayor due to the opponent’s position, the mayor should adopt the opponent’s position.
Goal: Use the negation test (explained below) to find the option that best reflects an assumption that MUST be made for the argument to work.

Analysis:

General comments about assumption questions:

Assumption style questions deal with a gap between the premise(s) and conclusion. The assumption will bridge that gap. For example, take the following argument:

P1: The Lakers are the best team in basketball
( )
C: Therefore, the Lakers will win the championship

There is a gap between the premise conclusion. This gap can be filled by identifying the assumption that the best team will win the championship. If this assumption is placed within the gap, the conclusion follows.

Assumption questions come in two main varieties:

1. Necessary assumption: Here, the assumption is required in order to move from premise(s) to conclusion. Without this assumption, the conclusion does not follow. Using the negation test can be a useful strategy with necessary assumptions. Deny the answer choice and see if the conclusion becomes impossible. If so, then that is the correct answer.
2. Sufficient assumption: Here, the assumption guarantees that the conclusion will occur. However, the conclusion may also occur without the presence of the assumption

This argument assumes that the mayor’s popularity will increase if he adopts his opponent’s position against national chains in the downtown area.

The question stem uses the phrase “relies on” which is another way of asking for a necessary assumption. For necessary assumption questions, we will do the negation test.

How to do the negation test?
Deny the answer choice and see if the conclusion becomes impossible. If so, then that is the correct answer. For example, consider the following argument:

P1: All puppies are young mammals.
P2: (Assumption )
C: All puppies are cute

Answer choices:
All puppies have round eyes
All young mammals are puppies
Some young mammals are cute

To do the negation test, we deny the answer choice and see if the conclusion is still possible. If the conclusion is still possible, then the answer choice is not necessary, and therefore, is not the correct answer.

If we deny A and say that it is not the case that all puppies have round eyes (or some puppies do not have round eyes), is it still possible that all puppies are cute? Yes. So, answer choice A is not correct. If we deny B and say that it is not the case that all young mammals are puppies (or some young mammals are not puppies), is it still possible that all puppies are cute? Yes. So, answer choice B is not correct. If we deny that some young mammals are cute by saying no young mammals are cute, is it still possible that all puppies are cute? No. Given that all puppies are young mammals, in order for all puppies to be cute, then it must be the case that some young mammals are cute. So, answer choice C is a necessary assumption for this argument.

Although I will use the negation test for evaluating the answer choices below, a more direct way of doing this question is to look to see if the answer choices are relevant. The argument connects the position on forbidding/limiting chains in the downtown area to the mayor’s increase in popularity. As with so many of these critical reasoning questions, seeing the connection between the premises and conclusions is key. Here is a quick breakdown of the argument at hand:

Argument structure:
(P) = Premise/Evidence/Support (C) = Conclusion

P1: Opponent is more popular than the mayor because of opponent’s position against national chains in the downtown
(P2: Assumption )

C: If the mayor wants to increase his popularity and win the election, the mayor and his party should support limiting national chain stores in the downtown area

Let’s see how each option holds up to the negation test and relevancy check:

A. The mayor, by announcing a limit on national chain stores downtown, would increase voter turnout in the upcoming election.
Incorrect. Suppose there was not an increase in voter turnout. The mayor could still win the election by becoming more popular than his opponent. His winning the election does not depend on voter turnout but on increasing his popularity. Therefore, answer choice A is not a necessary assumption.

B. Some voters who plan to support the mayor’s opponent would not do so if the mayor limits national chain stores downtown.
Correct. Suppose we denied this answer choice by saying that the mayor’s support for limiting national chains would not alter voter support for the opponent. Then, there is no way for the mayor to increase his popularity and win. By denying this answer choice, the conclusion becomes impossible. Therefore, answer choice B is a necessary assumption.

C. The mayor has the authority to limit the opening of national chain stores downtown.
Incorrect. Suppose the mayor did not have the authority to limit the opening of national chains in the downtown area. It is still possible that his adopting his opponent’s position could win voter’s over to the mayor’s side, regardless of his lack of authority to limit national chains. Therefore, answer choice C is not a necessary assumption.

D. The plan to forbid national chain stores downtown is supported by a majority of the town’s residents.
Incorrect. Suppose the plan to forbid national chain stores in the downtown is not supported by the majority of the town’s residents. The issue is increasing the mayor’s popularity relative to his opponent. If his opponent is more popular because of this one issue, then the mayor can still increase in popularity by changing his stance, even if the majority do not support this position. Therefore, answer choice D is not a necessary assumption.

E. Most voters who currently plan to vote for the mayor’s opponent do not currently know of the mayor’s position on this issue.
Incorrect. Suppose that most of the voters who plan on voting for the opponent did know the mayor’s position. The mayor could still increase in popularity by sniping some of the opponent’s supporters if he changes position. Therefore, answer choice E is not a necessary assumption.


Key Takeaways:
1. Use the negation test for necessary assumption question
2. Pay attention to relevance by noticing how the premises connect to the conclusion. In this question, only answer choice B properly connected popularity with limiting national chains in the downtown area


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