#23 - An antitheft device involving an electronic homing

[amazagri]

A and C in my humble opinion can be suggestive of a potential explanation. If thieves are less cautious, that would mean more likely to get caught - ergo an increase in arrest rate. We would have to assume that a large number of thieves are caught stealing the small amount of cars with the device, which is somewhat of a big assumption to make this work. So the device greatly increase the apprehension + large number of thieves tried to steal the cars with the device and were caught = small amount of cars result in a dramatic decrease in car theft.

C also implys an increase in apprehension since we know the device greatly increases and in the past they were rarely. However, the word "before" is vague. 30 years ago the apprehension was rare, but prior to the release of the device it was high? So clearly we have the assume the before in this context is right before the invention of the device. Supplement this with the same assumption we made with A - most or a large number of thieves tried to steal the cars with the device and were caught, which led to a decrease.

E on the other hand also requires as to assume that the city in the stem are included in the "most." Ultimately, all answer choices require an assumption. However, E is the one that makes a much simpler assumption to justify and the word choice of E is more in line with "small amount of cars (few thieves) and dramatic decrease (majority of car theft).

[amazagri]

A and C in my humble opinion can be suggestive of a potential explanation. If thieves are less cautious, that would mean more likely to get caught - ergo an increase in arrest rate. We would have to assume that a large number of thieves are caught stealing the small amount of cars with the device, which is somewhat of a big assumption to make this work. So the device greatly increase the apprehension + large number of thieves tried to steal the cars with the device and were caught = small amount of cars result in a dramatic decrease in car theft.

C also implys an increase in apprehension since we know the device greatly increases and in the past they were rarely. However, the word "before" is vague. 30 years ago the apprehension was rare, but prior to the release of the device it was high? So clearly we have the assume the before in this context is right before the invention of the device. Supplement this with the same assumption we made with A - most or a large number of thieves tried to steal the cars with the device and were caught, which led to a decrease.

E on the other hand also requires as to assume that the city in the stem are included in the "most." Ultimately, all answer choices require an assumption. However, E is the one that makes a much simpler assumption to justify and the word choice of E is more in line with "small amount of cars (few thieves) and dramatic decrease (majority of car theft).

So i believe in this context, E is simply the one and best answer out of them all.

[amazagri]

I actually got an explanation for this from LSAC themselves, so i'm putting it on here for your alls viewing pleasure



This is in reply to your email correspondence dated February 3, 2020 regarding question 23 in section 4 of The Official LSAT PrepTest 86. Members of the Assessment Development staff at LSAC have carefully reviewed this question and determined that it is not flawed and that the credited response, (E), is the one and only best answer.

You begin your inquiry with a question about the instructions for the Logical Reasoning sections of the LSAT, and specifically about the following statements in these instructions: "For some questions, more than one of the choices could conceivably answer the question. However, you are to choose the best answer; that is, choose the response that most accurately and completely answers the question." The purpose of these statements is simply to inform test takers that while multiple answer choices may appear on superficial review to be potential correct answers to a question, it will always be the case that on more careful review, there will be one and only one best answer. This is true of question 23.
Question 23 asks you to identify the answer choice which, if true, would most help to explain the dramatic drop in car thefts in cities where only a small percentage of car owners have the new antitheft device installed in their vehicles. You suggest that options (A) and (C), as well as the credited response (E), could all be regarded as potential correct answers.

Let's consider options (A) and (C) first. Both options, as you note, could be taken to suggest that the apprehension of car thieves has increased as a result of the new antitheft device. You assert that in order to view either (A) or (C) as providing an explanation for the noted dramatic decrease in car thefts, "one would have to assume that [most]/[a large number of] thieves are stealing cars with the device." However, such an assumption is insufficient to provide either (A) or (C) with much explanatory value. In the first place, bear in mind that the cities that have seen this dramatic drop in car thefts are "cities where only a small percentage of car owners nave
the device installed." So, your assumption would need to be supplemented with some further assumption as to how "most" or "a large number of" thieves could be caught stealing cars with the device if there are relatively few cars that are in fact equipped with the device.

In the second place, an increase in the number of thieves apprehended does not allow us to infer with any degree of certainty the effect such an increase would have on the
number of car thefts. Before one can reasonably draw such an inference, one needs to know something about the proportion of car thefts the recently apprehended thieves are (or were) responsible for. If the increase in apprehensions is an increase in the apprehension of first-time thieves, or thieves
who in the past only rarely stole cars, then the increase in apprehensions cannot be taken to provide an adequate explanation for the overall decrease in thefts. So, while it is true that (A) and (C) might be suggestive of a potential explanation for the dramatic impact of the antitheft device, neither provides a very firm foundation for a satisfactory explanation.

Consider now the credited response (E). Again, if we take the decrease in car thefts to be correlated with the apprehension of car thieves, then in a city where the majority of car thefts are committed by a few very experienced car thieves, the apprehension of a few or possibly even just one of these thieves could reasonably be expected to lead to a dramatic drop in the overall number of car thefts. That is, unlike (A) and (C), option (E) does provide us with information that enables us to infer with some degree of certainty that an increase in the apprehension of car thieves in these cities would lead to a dramatic decrease in the number of cars stolen. You are right that option (E) relies on the assumption that the cities described in the passage are among "most cities," but this is a perfectly reasonable assumption. In light of these considerations, option (E) is the one and only best answer, and is therefore the credited response.

When reviewing LSAT questions keep in mind that they are thoroughly vetted by content experts who must all agree that the credited response for each question is the one and only best answer. In addition, all questions on PrepTests, including the free preparation materials on the LSAC website and at Khan Academy, have been scrutinized by thousands of test takers and many others who follow the test.

Thank you for your interest in the LSAT.

Sincerely,

James Lorié

Director of Assessment Development

JL/mll

[appletree]

Hello!
I can see how E is the best choice in this case, but I am still a bit confused on the explanations provided for the elimination of C.
One person on here said that C would make the paradox worse since in the past anti-theft devices didn't really work, so why would thieves suddenly start caring. I definitely get that, but I had a different interpretation of it.
I thought of it as in the past the anti-theft didn't really work so thieves kept going, but now there is a new device that greatly increases the chances of even the best thieves getting caught, they are worried (even if the chances of a car having the new device are small). And therefore, the theft rates dropped dramatically.
I thought this line of reasoning was fine because the stimulus never said that the thieves didn't know about the new device and its potential.
Could someone explain why this reasoning is incorrect? Thank you!

[amazagri]

nothing about the stem talks about getting worried. The stem only talks about tracking and getting apprehended - or at least apprehended is implied.

[Rachael Wilkenfeld]

Thank you so much, amazagri, for sharing that response from LSAC.

And appletree, you are adding information that isn't given in the answer choice. We know in the past antitheft devices didn't really work to catch thieves. That doesn't tell us anything about the knowledge thieves have about new antitheft technology or it's frequency of use. You can't assume worry or other mental states about the thieves, or that they have any specific knowledge. Answer choice (E) doesn't make any similar assumptions. It works to explain the paradox no matter if the thieves know or they don't know.

[menkenj]

My reasoning for choosing E was that if the majority of car thefts are by a few experienced thieves, then when the device was introduced, it is likely that some of them would have been apprehended and thus, cannot steal anymore cars while in custody. Also then the remaining thieves are also potentially aware of the devices (bc criminals likely form networks and talk to each other) and are thus deterred from stealing in that area. All in all that means the car theft rate decreases despite only a small % car owners with devices installed.

[ArizonaRobin]

My reasoning for choosing E was that if the majority of car thefts are by a few experienced thieves, then when the device was introduced, it is likely that some of them would have been apprehended and thus, cannot steal anymore cars while in custody. Also then the remaining thieves are also potentially aware of the devices (bc criminals likely form networks and talk to each other) and are thus deterred from stealing in that area. All in all that means the car theft rate decreases despite only a small % car owners with devices installed.

THIS is exactly right, except you don't even need the remaining thieves to become aware. If the majority of thefts are being committed by a few thieves, then apprehending even one of them due to the new device would cut down quite a bit on auto thefts. I feel like previous commenters really over-complicated this problem.

[ashpine17]

Why doesn't A explain the dramatic drop? If thieves tend to be less cautious wouldn't that increase their chances of getting caught? Hence the drop in thievery?

[Adam Tyson]

The problem with answer A, ashpine17, is that it fails to explain why there has been a dramatic drop in car thefts despite only a small percentage of car owners having installed the device. We need an answer that explains not just that some thieves are caught, but that the impact of the device is disproportionately high when compared to the extent to which the device has been put into use. For answer A to have any impact on that unusual ratio, we still need to know something like what answer E says, that the thieves who are caught are responsible for a large percentage of all car thefts.