shobhitkh wrote:
Over the past few years, violent crime has decreased dramatically in City X. During this period, there has also been an increase in the number of late-night street vending licenses granted by the city, thereby increasing the number of people on the streets at night. Therefore, the reduction in violent crime must be related to the increase in vending licenses.
Which of the following, if true, most seriously casts doubt on the argument above?
(A) The amount of nonviolent crime in City X has not changed much over the past few years.
(B) A reduction in crime also causes more pedestrians to be out on the streets in the evenings.
(C) The number of street vendors in City X has increased steadily during the period in question.
(D) During the past few years, City X has reduced the amount of city taxes street vendors must pay.
(E) Last year, City X increased the number of police officers working at night.
sid0791Aviral1995I wouldn't invest too much time in this question.
(E) does give an alternative reason but with 'last year' it isn't valid. It doesn't explain dramatic decrease of "past few years"
Also, the conclusion
"the reduction in violent crime must be related to the increase in vending licenses." just says that the two are related. Which one causes the other isn't given. Decrease in crime could make late-night business more viable and more people at night could lead to decrease in crime.
That said, the argument does seem to be suggesting that more people at night is the reason crime has decreased else there was no need to mention
"...thereby increasing the number of people on the streets at night"If we assume that the author is trying to say that more vendors caused decrease in crime, then (B) helps.
(B) A reduction in crime also causes more pedestrians to be out on the streets in the evenings.
Tells us the relation is the other way around.
But the conclusion just says "they are related" so if we were to assume that the author just meant that they are related, then (E) would have made sense but with "last few years".
As for (C) and (D), in any case they are wrong.
(C) The number of street vendors in City X has increased steadily during the period in question.
A relation need not be proportional. Perhaps vendors increased steadily but crime decreased dramatically.
(D) During the past few years, City X has reduced the amount of city taxes street vendors must pay.
This introduces a new variable "city taxes" which impacts "number of vendor licenses". But it doesn't strengthen or weaken the relation between "number of vendor licenses" and "crime".