Official: Six months ago, the fines for parking violations on the city's streets were raised to help pay for the par...

Ross-Rinehart on August 19, 2021

On an "Errors in Reasoning" question, when an answer choice starts with "fails to establish" ask yourself the following questions: (1) Is this something the author doesn't establish as a premise?, and (2) If this weren't true, would it weaken the author's argument? If "yes" to both, the answer choice is correct. If "no" to either, it is wrong.

In this case, the author never establishes as a premise that "that decrease in parking violations was not due to the availability of additional parking spaces." Further, if that weren't true — if the decrease in violations *was* due to the availability of additional parking spaces — then the author's conclusion would be weakened. We would have no reason to think that a higher fine would result in fewer violations, since it was the more parking spaces — not the fine itself — that had decreased the violations.

The answer choice you submitted ("failed to establish that the initial decrease of parking violations was due to the availability of additional parking spaces as a direct result of using the fines to build the parking garage") would be correct if you instead wrote "fails to *consider* that the initial decrease of parking violations was due to the availability of additional parking spaces as a direct result of using the fines to build the parking garage." When an answer choice starts with "fails to consider" (or "overlooks the possibility"), the two questions we ask are slightly different than what we ask when the answer choice says "fails to establish": (1) Is this something the author doesn't establish as a premise? (2) If this *was* true, would it weaken the author's argument? If "yes" to both, the answer choice is correct. If "no" to either, it is wrong.

The reason we need to modify the questions is that an argument is not flawed if an argument "fails to establish" something that could possibly weaken the conclusion. Quite the opposite: an argument is flawed when it "fails to establish" that something that could weaken the conclusion is not actually a problem. This is why the second quesiton we ask on "fails to consider" answer choices must be "If this *weren't* true, would it weaken the author's argument?"