LSAT Explanation PT 22, S2, Q14: Charles: During recessions unemployment typically rises.

LSAT Question Stem

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

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

First, let's analyze the passage. Charles presents an argument that during recessions, unemployment rises, and therefore, air pollution due to automobile exhaust decreases because fewer people commute in cars to jobs. This is his conclusion. Darla challenges his argument by pointing out that during a recession, fewer people can afford to buy new cars, and older cars tend to emit more pollutants.

To make this more accessible, let's use a simple example: Imagine a town where everyone uses cars to go to work. During a recession, some people lose their jobs and stop using their cars to commute. Charles argues that this would lead to less air pollution. Darla counters by saying that since people can't afford new cars during a recession, the remaining cars on the road might be older and more polluting.

Our "Evaluate" question for this argument could be: "Do the decreases in car usage due to unemployment outweigh the potential increase in pollution from older cars still being used?"

Now, let's discuss the answer choices for the question, which asks us to identify an assumption on which Charles's argument depends.

a) This answer choice is not necessary for Charles's argument. Even if people who have never been employed continue driving at the same rate, it doesn't affect the relationship between unemployment and air pollution that Charles is arguing for.

b) Charles's argument focuses on air pollution due to automobile exhaust specifically, so this answer choice is not relevant. He doesn't need to assume that most air pollution is caused by cars used for commuting.

c) This answer choice is not necessary for Charles's argument. He doesn't need to assume that most people who are employed do not use public transportation. As long as some people who lose their jobs during a recession stop using their cars to commute, his argument could still hold.

d) This is the correct answer choice. Charles needs to assume that any decrease in car usage due to unemployment is not offset by an increase in car usage for other reasons. If people started using their cars more for other reasons during a recession, it could negate the decrease in air pollution that Charles argues for.

e) Charles doesn't need to assume that a higher proportion of people who commute in cars lose their jobs during a recession. As long as some people who drive to work lose their jobs, his argument about decreased air pollution could still hold, even if most people were not driving.

In summary, the correct answer choice is (d), as Charles's argument depends on the assumption that the decrease in car usage due to unemployment is not offset by increased car usage for other reasons during a recession.