Question

Difficulty: Very hardNecessary Assumption

Political scientist: To increase voter turnout in the upcoming municipal election, the city council mailed an information packet to all registered voters detailing the policy positions of the mayoral candidates. The council predicts turnout will increase, reasoning that voters who understand candidates' platforms are more likely to participate. However, behavioral studies show that providing voters with highly detailed policy comparisons generally increases their perception of ideological overlap among candidates. Because voters are significantly less likely to vote when they perceive little ideological difference between candidates, the council’s initiative will actually result in lower overall voter turnout than there would have been without the mailer.

Which one of the following is an assumption on which the political scientist's argument depends?

  1. Any increase in voter turnout resulting from voters gaining a better understanding of the candidates' platforms will not exceed the decrease in turnout caused by the increased perception of ideological overlap.Answer
  2. B
    If voters are provided with highly detailed policy comparisons, they will inevitably perceive less ideological difference between the candidates than they did prior to reading the comparisons.
  3. C
    The information packet mailed by the city council contains the only information that most voters will evaluate regarding the ideological differences among the mayoral candidates.
  4. D
    Voters who do not receive highly detailed policy comparisons are unlikely to perceive a significant degree of ideological overlap among local mayoral candidates.
  5. E
    The behavioral studies demonstrating the effects of highly detailed policy comparisons were conducted exclusively on voters participating in municipal elections.

Answer

The assumption that any increase in turnout from better understanding the platforms will not exceed the decrease in turnout from perceiving ideological overlap.
The correct answer acts as an essential bridge between competing causal forces in the stimulus. The author explicitly concedes that the mailer achieves a goal (understanding platforms) that normally increases voter turnout. However, the author concludes that the ultimate result will be a net decrease in turnout because of a negative side effect (perceived overlap). For this definitive conclusion to hold, it is absolutely required that the positive effect does not completely offset or exceed the negative effect. If we negate this statement—saying the increase from understanding DOES exceed the decrease from perceived overlap—then the net turnout would rise, completely destroying the author's conclusion.

Step-by-Step Solution

1
Identify the conclusion of the argument.
The conclusion is that the council's initiative will result in lower overall voter turnout than there would have been without the mailer.
This is the final claim the political scientist is trying to prove against the council's prediction.
2
Identify the premises supporting the conclusion.
Premise 1: The mailer increases platform understanding, which generally increases turnout. Premise 2: The mailer acts as a detailed comparison, which increases perceived overlap. Premise 3: Perceived overlap decreases the likelihood of voting.
Mapping the premises reveals the causal mechanisms the author believes are at work.
3
Identify the logical gap in the argument.
The author acknowledges a factor that increases turnout but concludes the net result will be a decrease in turnout.
To jump from 'mixed effects' to an absolute 'negative net outcome', the author must be weighing the opposing factors implicitly.
4
Apply the Negation Test to find the necessary assumption.
If the positive factor (understanding platforms) actually exceeds the negative factor (perceived overlap), the net turnout would increase, destroying the author's conclusion. Therefore, the author must assume the positive factor does not exceed the negative one.
A necessary assumption is one that, if proven false, causes the argument's logic to collapse.

Key Concept

Necessary Assumption (Negation Test and Balancing Causal Forces)
Rate this question