A city council member argues: 'To improve public safety in our downtown area, we must increase police presence. Crime statistics show a direct correlation between the number of police patrols and a decrease in reported incidents.' Which of the following, if true, most strengthens the city council member's argument?
- AIncreased police presence does not deter all types of criminal activity.
- BThe correlation observed in the statistics holds true even when accounting for other variables like economic conditions.
- CThe city's downtown area has a higher crime rate than other parts of the city.
- DOther cities with increased police presence have also seen crime rates fall.
Show answer & explanationAnswer & explanation
Correct answer: B. The correlation observed in the statistics holds true even when accounting for other variables like economic conditions.
The council member argues for a causal link (more police -> less crime) based on a correlation. Option D strengthens this causal link by explicitly ruling out other potential causes (like economic conditions) that might explain both increased patrols and decreased crime. By showing the correlation holds even with other variables accounted for, it bolsters the idea that police presence is the actual cause.
Why the other options are wrong
- A. This weakens the argument by suggesting limitations to the effectiveness of increased police presence.
- C. This describes the current state of downtown crime but does not strengthen the argument that *increasing* police presence will *cause* a decrease.
- D. This provides anecdotal evidence of a similar correlation elsewhere, which offers some support but doesn't directly address the validity of the causal link within this specific city's statistics.
Strengthening a Causal Argument
To strengthen a causal argument, one can provide evidence that eliminates alternative causes, establishes the cause precedes the effect, or shows a mechanism for the causality.
- Rules out alternative explanations
- Confirms cause-effect order
- Provides a plausible mechanism
Memory trick: Seal the causal leak, eliminate other explanations!