In each of the past five years, Barraland's prison population has incr

In each of the past five years, Barraland’s prison population has increased.

In EACH of the last 5 years, the number of people in B’s prisons has increased.

Yet, according to official government statistics, for none of those years has there been either an increase in the number of criminal cases brought to trial, or an increase in the rate at which convictions have been obtained.

According to govt statistics, for each of these five years,

1. No increase in the number of criminal cases brought to trial
2. No increase in the rate of convictions

(This statement rules out a couple of reasons for the increase in the prison population. Perhaps, there is another reason. Or perhaps, the govt statistics are incorrect!)

Therefore, the percentage of people convicted of crimes who are being given prison sentences is on the increase.

This is the conclusion.

After eliminating two potential reasons for the increase in the prison population, the author concludes with another reason. In a way, the reasoning goes like this:

Since X and Y cannot be the reason for the event, Z (another reason for the event) must have happened.

This statement talks about the percentage of people convicted of crimes who are being given prison sentences.

This percentage = (Number of people convicted of crimes who are being given prison sentences)/ (Total Number of people convicted of crimes)

The second statement above ruled out that the total number of people convicted of crimes has increased. This third statement, the conclusion, talks about another potential reason for the increased prison population – of every 100 people convicted, more people are being given prison sentences, e.g., if previously 50 people were given prison sentences for every 100 convictions, now 70 people are being given prison sentences for every 100 convictions.

The GIST

The argument quotes a situation (prison population increased).

The argument then rules out a couple of explanations for the situation.

The argument, thus, concludes that another potential reason must be the case.

The GAPS

A clear gap in the argument above is that there could be some fourth reason which explains the situation. One reason that comes to mind is longer prison sentences. If we get to know that courts are handing out longer prison sentences, we’ll have an explanation for the increase in the prison population. Thus, in such a case, we won’t be able to arrive at the conclusion.

Another gap is that we don’t know whether the government statistics are reliable. If they are not, one of the two reasons cited in the second sentence could explain the increase in the prison population.

There could be more gaps.





(A) In Barraland the range of punishments that can be imposed instead of a prison sentence is wide.

Incorrect. This option has NO IMPACT on the argument.

The reason this option is wrong is that it doesn’t say anything was different for the last five years compared to previous years. Without anything different, we wouldn’t have any explanation for the increased prison population.

(B) Over the last ten years, overcrowding in the prisons of Barraland has essentially been eliminated as a result of an ambitious program of prison construction.

Incorrect. This option has NO IMPACT on the argument.

The option says that because of more prison space, overcrowding in the prisons has been eliminated. The option doesn’t talk about the population in the prisons. It talks about population density in prisons.

The elimination of overcrowding due to more space in the prisons has no relevance to the argument, which is about explaining the reason for the increased prison population.

(C) Ten years ago, Barraland reformed its criminal justice system, imposing longer minimum sentences for those crimes for which a prison sentence had long been mandatory.

Correct. This option is in line with the first gap that I thought of.

Longer sentences could be another explanation for the increased prison population. And if we have this explanation, we don’t have a reason to believe in the conclusion, which presents a different explanation.

I believe you would have already paid attention to the fact that this option talks about a change that happened ten years ago, not five years ago.

Would that change have an impact five years later than when it came into existence?

Yes, if the change impacted prison sentences that were earlier for about five years and were revised to six or more years.

Do we know, for sure, that the change impacted these types of prisons sentences?

No.

However, we don’t need surety. We need an indication. Since the option talks about crimes for which a prison sentence had been mandatory, we have a reason to believe that we’re talking about multi-year prison sentences.

Thus, this option casts doubt on the conclusion by offering a different explanation.

(D) Barraland has been supervising convicts on parole more closely in recent years, with the result that parole violations have become significantly less frequent.

Incorrect. This option has NO IMPACT on the argument.

Like the variation A1 we created, this option gives us a reason why the prison population should have decreased in the last five years. (Why? Because if there are fewer parole violations, there will be fewer parole revocations. If there are fewer parole revocations, there will be fewer people readmitted to the prisons. In such a case, the prison population should decrease)

However, we know that the prison population has increased. We’re looking for an explanation for the increase.

An option indicating that the population has not even increased is irrelevant to us.

Some believe this option weakens the argument since it doubts whether the prison population has increased. However, this reasoning is flawed. The argument is concerned with a potential explanation for an event. The argument cannot be challenged by saying that perhaps the event did not occur.

(E) The number of people in Barraland who feel that crime is on the increase is significantly greater now than it was five years ago.

Incorrect. This option has NO IMPACT on the argument.

The option compares, across two time periods, the number of people who feel that crime is on the increase. This number is much greater now than it was five years ago.

Does this indicate that there is more crime now than five years ago?

To some extent, it does.

Can an increase in crime explain the increased prison population?

Yes, if increased crime leads to more criminal cases brought to trial. However, the argument has already said that there has been no increase in the number of criminal cases brought to trial.

Thus, this option has no impact on the argument.

Hi Shami

The stimulus can be broken down in this fashion:

Premises:
i) Barraland's prison population has increased in each of the past five years.
ii) There has been no increase in number of criminal cases.
ii) There has been no increase in conviction rate.

Conclusion: Proportion of convicts being given prison sentences is increasing.

(ii) & (iii) together mean that number of people being sent to prison has remained constant. Since (i) states prison occupation is increasing, it can only be because number of prisoners being released has been reducing.

Option (C) states that, for the same crime, the length of prison sentences being given was increased abruptly ten years ago. This would explain why fewer prisoners are being released from prison - because of the longer sentences, they would not yet have completed their term. This provides an alternative explanation for (i) and hence weakens the conclusion.

Hope this helps.

Conclusion : Clearly, therefore, the percentage of people convicted of crimes who are being given prison sentences is on the increase.



Answer : (C) Ten years ago, Barraland reformed its criminal justice system, imposing longer minimum sentences for those crimes for which a prison sentence had long been mandatory.

Target to weaken (conclusion): Clearly, therefore, the percentage of people convicted of crimes who are being given prison sentences is on the increase.

--

A- In Barraland the range of punishments that can be imposed instead of a prison sentence is wide. Irrelevant, still doesn't explain the reason behind the increase, thus incorrect.
B- Over the last ten years, overcrowding in the prisons of Barraland has essentially been eliminated as a result of an ambitious program of prison construction. Irrelevant
C- Ten years ago, Barraland reformed its criminal justice system, imposing longer minimum sentences for those crimes for which a prison sentence had long been mandatory. It essentially implies that there are more people in prison since the implementation of the reform, which explains the increase over time, correct.
D- Barraland has been supervising convicts on parole more closely in recent years, with the result that parole violations have become significantly less frequent. Irrelevant
E- The number of people in Barraland who feel that crime is on the increase is significantly greater now than it was five years ago. Irrelevant

--

Thanks for sharing.

I liked your elimination, however I feel that the reason for eliminating is not because it is out of scope but because it is a strengthener. It is giving you a reason that people who are on parole are not likely to come back, and hence crowding in the prison could be because of the percentage of people getting convicted is on increase.
And.. remember Answer choices in Weaken and Strengthen questions are likely to be Out of Scope.

Premise: Prison person increased, Criminal cases not increased, Convictions not increased.
Conclusion: So, Prisoners/convicts must have increased.

If I prove that prisoners increased not because of convicts but because of something else, then that would weaken the conclusion.

In each of the past five years, Barraland's prison population has increased. Yet, according to official government statistics, for none of those years has there been either an increase in the number of criminal cases brought to trial, or an increase in the rate at which convictions have been obtained. Clearly, therefore, the percentage of people convicted of crimes who are being given prison sentences is on the increase.

Which of the following, if true, most seriously weakens the argument?

A. In Barraland the range of punishments that can be imposed instead of a prison sentence is wide.
If range is high, then why prisoners increased?
B. Over the last ten years, overcrowding in the prisons of Barraland has essentially been eliminated as a result of an ambitious program of prison construction.
Even if a program has been eliminated, its relation with the convict-prisoner hasn't been mentioned.
C. Ten years ago, Barraland reformed its criminal justice system, imposing longer minimum sentences for those crimes for which a prison sentence had long been mandatory.
Bingo ! Prisoners are living longer than they used to before.
D. Barraland has been supervising convicts on parole more closely in recent years, with the result that parole violations have become significantly less frequent.
Violations less frequent-> low number of convicts-> then why prisoner population increased?
E. The number of people in Barraland who feel that crime is on the increase is significantly greater now than it was five years ago.
Irrelevant.

I think this can be solve by looking at the assumption = A.
Conclusion = B.
A causes B.
Lets the stats be the way it is.
A= Clearly, therefore, the percentage of people convicted of crimes who are being given prison sentences is on the increase
B = Barraland’s prison population has increased

Can I find another cause for the increase in population (B) ?

C- since not much people are leaving so population increased
D- Less violation, less population in jail - so this option is out

Hi Deeptanshu

Option (B) is frankly irrelevant to the point being made in the stimulus. The stimulus talks about "Barraland's prison population", ie; total number of people in prisons in Barraland. Option (B), on the other hand, talks about "overcrowding in the prisons of Barraland" ie; number of prisoners per prison (or, to be more specific, number of people in prisons relative to their capacity) in Barraland. Hence option (B) does not impact our conclusion in any manner.

Option (C), the correct answer, states that 10 years ago, longer prison sentences started being imposed. Now, if we start imposing longer prison sentences today (for crimes which have prison sentences), prison population would not increase today itself but at some point in future, when prisoners sentenced today would have started getting released under the earlier model but are still in prison due to the longer prison sentences imposed today. This lag, presumably, is five years in Barraland!

Hope this clarifies.

Hi,
I did get the correct answer through the POE but I am unable to understand what the option meant.

Kindly help!

CrackVerbalGMAT I rejected B as the question stem states that Last 5 years this this and that happened so whatever should weaken must be an answer choice telling something that took place 5 years before. Is option B perfectly okay? Can you help me understand why the stem stated 5 years but the answer stated 10 years

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.