#24 - Over the last 25 years, the average price paid for a

[Administrator]

Complete Question Explanation

Weaken, #%, CE. The correct answer choice is E.

In this weaken question, we are looking to undermine the conclusion's explanation of a certain numerical observation. What we've been observing over the last 25 years is offered in the first sentence (the premise): average new car price has risen steadily in relation to average individual income. In other words, the average price of a new car has been going up faster than the average individual income has been going up. The conclusion in the second sentence offers a causal driver of this change, i.e. a reason why this is the case: individuals are spending a larger amount relative to their incomes (a larger percentage of their incomes) than they used to spend on cars 25 years ago. This is certainly one possible cause of the change in relative new car price. But it is not the only possible cause. A very good way to attack this conclusion would be to suggest an alternate explanation (an alternate cause) of the change in relative new car price.

There is a subtle shift in language in the argument, and an attentive test-taker who catches that shift will be rewarded. The first sentence talks about the change in relative price "paid for a new car," without saying anything about who (or what) is paying that price. The second sentence talks about the price individuals pay for a new car. The author has thus assumed that individuals are the ones paying the higher relative prices the first sentence refers to. But what if some other entity (like a corporation) were buying more higher-priced cars? Then individuals would have nothing to do with the rising relative price. This would be an excellent prephrase.

Answer Choice (A): This answer choice is incorrect, because even if households had more wage-earners than they used to have, that wouldn't necessarily undermine the notion that, judged on an individual basis, each individual is paying a higher percentage of their income than they used to pay for a new car. For this answer choice to affect the scenario, we would need further information that households were pooling their incomes and purchasing cars (which would undermine the idea that individuals are paying more, and suggest that households are responsible for the relative price increase in new cars).

Answer Choice (B): Since the argument is about what is driving the relative price increase in new cars, information about the number of cars sold is irrelevant, and this answer choice is thus incorrect.

Answer Choice (C): This answer choice is consistent with the factual scenario described, and could make it somewhat more likely that individuals paying higher prices relative to income are in fact responsible for the relative price change in new cars. This cannot be a Weaken answer and is therefore incorrect.

Answer Choice (D): This answer choice is irrelevant, because it merely discusses changes in the number of new cars sold and in the population, not changes in price of new cars and income of individuals.

Answer Choice (E): This is the correct answer choice. This answer choice fits the prephrase. If more new cars are being sold to entities other than individuals (like, for example, corporations), then it could very well be that those entities are paying much higher prices for new cars and are entirely responsible for the relative price change in new cars. Since this answer poses a potential alternate cause (to the one offered by the argument's conclusion), it weakens the argument and is correct.

[alee]

Hi Guys,

Re. the question in the title, is the 'key' to the question the shift from talking about amount relative to income spent on buying NEW cars, to amount relative to income spent on buying cars (in general)? This would open up the possibility that people 25 years ago on average bought some other cars (aside from new ones), and hence the amount they spent on a NEW car wouldn't necessarily indicate the avg. amount relative to income spent on cars in general (i.e. maybe they bought a few second hand cars on average too).

Otherwise I am confused why (E) is the correct answer.

Thanks!

[Adam Tyson]

Alee, this one is a numbers and percentages question that does a pretty good job of isolating new car purchases from car purchases overall. Notice how consistent the author is in referring to only new car purchases throughout the stimulus.

The key here is the introduction in the conclusion of a new data point - individuals buying new cars. The premise spoke about individual income, but gave us no data on what percentage of new car sales were to individuals. The argument might work if the proportion of new car sales to individuals was the same today as it was 25 years ago, but imagine this scenario - as average car prices have gone up, the most expensive cars (the ones pulling up the average price) are being bought more and more by corporations and not by individuals. What if only the cheapest cars, perhaps even ones that are less expensive on average than the cars sold 25 years ago, are being bought by individuals today rather than groups? That would do serious damage to the argument's conclusion, since it was about the percentage of individual income being spent by individuals on new cars.

Hope that helped!

Adam M. Tyson
PowerScore LSAT Instructor

[alee]

Thanks Adam, that was very helpful.

[moshei24]

The way I understand this argument is that over the last 25 years the average price to pay for a new car has increased on average more than the increase in average individual income. And based on this increase the argument also assumes that because the average price paid for a new car has increased more than the average individual income has increased that an individual is likely on average to pay a larger amounts relative to their incomes by a car then they did 25 years ago. And the reason for this is because the cars costs more today then they did 25 years in proportion to their individual income. As you could see my understanding of the stimulus is a little bit shaky. So if you could please explain what the stimulus is saying and why answer E is the best answer that'll be great. I chose A and I think if I completely understand the stimulus, it will make sense. Though, if you could explain why a is wrong in relation to how you explain the stimulus, I would greatly appreciate that. Thank you.

[Adam Tyson]

I think your understanding of the stimulus is spot on, moshei, but your interpretation of the answers is where we need a little help.

The problem with A is that the stimulus deals with individual income - when an individual buys a car today, he is, on average, paying a larger portion of his individual income that he would have 25 years ago. The fact that he might be in a household with more than one income, possibly making it easier for him to make that purchase, doesn't change the basic fact that he is still paying a higher portion of his individual income for that car. Household income does nothing to weaken the argument that is only about individual income.

E is a hard answer to understand for a lot of my students. Think of it this way - what if the increase in the average price of cars has been because of just one model of car that costs a whole lot more than anything else. It's a $5 million Rolls Royce that's pulling up the average price of cars. Now, imagine that no individuals ever buy that model - they are always purchased by corporations, perhaps, rather than individuals. Might individuals still be paying the same proportion of their income for new cars as they were 25 years ago, despite the increase in the average price of new cars due to that one expensive Rolls Royce?

That's an extreme way to look at answer E, but for most of my students who have had trouble with this question it has helped them to understand that they can weaken the argument by showing that individuals are still, generally, buying cars as inexpensive (relatively) as they were 25 years ago.

Hope that clears it up for you!

Adam

[moshei24]

I'm not sure. When I looked back at the question a few hours after posting this, I understood it like this:

The premise is stating that over the past 25 years, the avg new car price has increased proportionally more than individual income.

They then make a jump from saying that the avg overall prices increased proportionally more to saying that the individuals also avg overall prices increased proportionally more. That requires the assumption that individual avg sales increased proportionally with overall avg sales.

(E) is saying that sales to individuals makes up a smaller proportion of avg new car sales than it did 25 years ago. That tells us that individual new car sales did NOT increase proportionally with the the overall new car sales, and since we don't have the assumption that is necessary for the conclusion to be true, the argument is weakened. Well, it's actually destroyed. Right?

Is that what you were saying?

Thanks!

-Moshe

[sarae]

Please explain why answer choice E is correct

[Adam Tyson]

Hey there sarae. This question involves some numbers and percentages, and a comparison. We're told that the average price paid for a new car has increased relative to average individual income, and the author then concludes that individuals must now be paying, on average, a higher portion of their income on their new car purchases. Sounds reasonable enough, doesn't it? Until we're told to weaken it, that is, which tells us that there must be a flaw in the reasoning somewhere.

The key to understanding the error here is in recognizing that the premise talks about the average price paid for a new car, with no reference to who or what is paying that price, while the conclusion is about "individuals" buying new cars. It might slip by you, since the premises were also about individual income, but they never said that cars were being bought only by individual purchasers, did they? So what would happen if corporations, for example, were now buying up fleets of very expensive cars - that would pull up the average price paid, while having no effect on the average amount paid by individuals! If individuals made up a smaller proportion of buyers, as answer E gives us, that would mean non-individuals (like my hypothetical corporations) made up a larger proportion than they used to, and that might help explain the rise in average price without requiring that any individuals pay more.

This one was a little sneaky - you have to read carefully to avoid making any unwarranted assumptions about the relationship between "average price paid" and "individuals who buy new cars."

Hope that helps to shed a little light on the subject!

[sarae]

that makes perfect sense! thanks!