Hardin argued that grazing land held in common (that is, open to any

Let's start by identifying the discrepancy between Hardin's argument and the results of the study:

• According to Hardin, grazing land held in common would always be used less carefully than private grazing land.
• However, according to the study, the common land was in better condition than the private land.

Now let's look at the details of the passage:

• Common grazing land is open to any user.
• According to Hardin, each individual rancher would be tempted to overuse common land. Why? Because each individual rancher would benefit from overusing the common land. Meanwhile, the costs of reduced land quality from overuse would be spread among all users.
• In other words, if a rancher overuses his/her own private land, he/she will bear the costs of the overuse. But if a rancher overuses common grazing land, the costs will be spread among ALL users. Thus, it seems as though ranchers using common land have more incentive to overuse the land and negatively impact the land quality.
• But the results of a study, which compared 217 million acres of common grazing land with 433 million acres of private grazing land, showed that the common land was actually in better condition. This goes against Hardin's argument. We need an answer choice that explains this discrepancy.

Which of the following, if true and known by the ranchers, would best help explain the results of the study?


This helps explain Hardin's point of view, but it does not explain why the results of the study do not match Hardin's argument. Eliminate (A).


Choice (B) tells us that it if, say, 20 ranchers are sharing some common land, then it is difficult to measure the cost in reduced land quality caused by any one user.

On the other hand, with private land, any cost in reduced land quality could be attributed to the rancher who owns the land. Determining the exact cost might be difficult, but we would not have to worry about dividing up the blame.

This information helps to explain Hardin's position. If (B) were NOT true, it might be easier to point a finger at any one rancher and say, "Hey, your overuse of the common land has cost us all X dollars!" That would make it harder for the ranchers to take advantage of the shared land.

But (B) does not explain the results of the study, so it should be eliminated.


Again, this helps to explain Hardin's position. Choice (C) gives us even more reason to expect that ranchers would try to overuse common land and that the private land would be in better condition. (C) does not explain the results of the study, so it should be eliminated.


According to Hardin, an individual rancher would have an incentive to overuse public grazing lands. Why? Because the rancher would accrue benefits from overusing the land, and the costs of the overuse would be spread among all users.

But according to choice (D), if an individual rancher tries to exploit the common land as described by Hardin, then the other users are likely to overuse the land to an even greater extent. As more and more users start to overuse the common land, the costs of overuse start to outweigh the benefits, even though those costs are spread among all users.

In other words, if only ONE rancher tries to exploit the system, then that rancher will benefit at the expense of the other users. But, if (D) is true and KNOWN by the ranchers, then all of the ranchers are aware that any such attempt will end up costing them in the long run. Thus, despite the temptation described by Hardin, the ranchers would not want to overuse the common land.

(D) explains the discrepancy, so keep this one.


We are not concerned with the number of acres of common and private land. We are only concerned with the condition of each type. Choice (E) is irrelevant, so eliminate this one.

(D) is the best answer.
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Conclusion: Common grazing land is in better condition than private grazing land even though common grazing land tend to be overused.

Which of the following, if true and known by the ranchers, would best help explain the results of the study?

(A): With private grazing land, both the costs and the benefits of overuse fall to the individual user.
- does not explain why common grazing land is in a better shape, or why private grazing land is in a poorer condition

(B): The cost in reduced land quality that is attributable to any individual user is less easily measured with common land than it is with private land.
- Again provides us with no useful information why common land is in a better shape

(C): An individual who overuses common grazing land might be able to achieve higher returns than other uses can, with the result that he or she would obtain a competitive advantage.
- out of scope.

(D): If one user of common land overuses it even slightly, the other users are likely to do so even more, with the consequence that the costs to each user outweigh the benefits.
- If this was true, common land would be less appealing to ranchers and they would rather use private grazing land than common grazing land. The consequence would be a lower quality private grazing land.

(E): There are more acres of grazing hand held privately than there are held in common.
- not important. All it tells us is there are more private grazing land than common grazing land.

(D) it is.

Must be D.

Rancher thinking: "Hey, Why shouldn't I let all my cattle graze on the commonland. Oh, wait a minute, if I do that, my neighbors will start doing the same and pretty soon the common land will be bare and I will have to graze all my cattle on my own land. hmmm... maybe that's not such a good idea!"

GMATNinja DmitryFarber

The reason i selected A is that I thought that if the individual costs in individual system is more , then the individuals would be less motivated to keep their area in a better shape... in contrast, the common land ppl share the expenses and so do not have much of a burden to keep the area in a better shape..
now the answer choice A just tells us that in individual system , individuals have to bear more.. the further reasoning i made based on motiavtion is wrong?? or did i take it too far??

Yes, you took this one too far. We have to be careful about adding further reasoning to what we're reading. This is one of the toughest things to keep up when taking the GMAT... but it's essential to take in the passage as directly as possible.

To illustrate, here's (A) again:

This choice adds more information to Hardin's argument by telling us what happens with private grazing land.

However, this choice does not tell us that "individuals have to bear more" (though I could be misunderstanding what you mean by this). It definitely doesn't state or suggest that "individual costs in individual system is more."

(A) says that in a case of overuse, the costs and benefits of that overuse both fall to the individual rancher. That's it. This choice adds no information or explanation about individual motivations. And this choice tells us nothing about how individual ranchers behave when using common grazing land. So there's nothing here that would help explain the study if it were true and known by the ranchers.

I hope this helps!
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The question stem is asking to explain the discrepancy between two scenerios?So if that discrepancy is resolved ranchers would know why the result was different? But option D do not provide any such explanation.

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Hi, Thanks for this explanation. Just a thing here, I am not ale to understand that even if farmers won't be involved in the practice of overgrazing on common land, I am not sure how it will finally justify the paradox of common land to be in Better condotion than private grazeland? Both of them can be at par in quality with this justification, but how does it prove "better" ? I am sure I am missing something here.

Mayank221133, we're not looking to explain why common land is in a better condition. We're looking to explain the discrepancy, which arises from the fact that despite the existing temptation for ranchers of the common land, the common land is in a better condition. Option D tells us that the ranchers don't give into this temptation as it has serious drawbacks. Of course, this doesn't really tell you why common land is in a better condition, but the discrepancy doesn't exist anymore and we can investigate further.

Which of the following, if true and known by the ranchers, would best help explain the results of the study?

Okay, so we have a 'help explain' question type. What do we know about these:
1) The passage will give us a surprising information going against prediction/data
2) Our job is to find the single statement which can help us resolve or explain the discrepancy.
3) We will get an additional information in the passage

Typical WA are answer options that:
1) Explain one cause and not other
2) Weaken the conclusion
3) Restate the stated condition

Hardin argued that grazing land held in common (that is, open to any user) would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individuals, while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.

Results have come opposite to what Hardin had predicted: The common grazing land is in better condition than Private grazing land.
What was the prediction: Since cost of common grazing land was shared among everyone, some people would be tempted to overuse it to maximise their profits.


(A) With private grazing land, both the costs and the benefits of overuse fall to the individual user.

This is a typical WA for such questions as it only explains part of the problem and not the whole comparison. We can eliminate this.

(B) The cost in reduced land quality that is attributable to any individual user is less easily measured with common land than it is with private land.

This we can easily remove. This isn't related to our paradox

(C) An individual who overuses common grazing land might be able to achieve higher returns than other users can, with the result that he or she would obtain a competitive advantage.

As mentioned above, this is a restate of the passage. Hence is a wrong answer. We need additional information

(D) If one user of common land overuses it even slightly, the other users are likely to do so even more, with the consequence that the costs to each user outweigh the benefits.

Okay, this nicely explains that overusing can have a snowballing effect and cost to EACH individual could outweigh the profit.

(E) There are more acres of grazing land held privately than there are held in common.

Okay, another nice way for GMAT to trick us, but again, this doesn't tell us why people didn't use the common grazing land to increase their profitability, even if they had privately held land.

The question doesn't ask us to "prove" anything at all -- instead, it just asks us which answer choice would "best help" to explain the results of the study.

(D) does exactly that -- it gives us a reason that farmers wouldn't overuse common land. Does this prove why common land is in better shape? Nope, but it doesn't have to go that far. (D) provides some information to help explain the results of the study, while the other answer choices don't help at all. So, (D) is the correct answer.

I hope that helps!
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I've read this question as a situation in which you have some sort of game theory scenario with D being a Pareto-optimal situation (or, in its weak configuration, a Nash equilibrium). No one could abuse of his part of land since there would be a lose-lose situation in the medium to long term. In short, everyone would need to cooperate to maintain a certain standard, thus avoiding the individual overuse.

That allowed me to choose the right answer and to exclude B since it was off topic. GMATNinja what do you think?

The others do not add useful information. (especially E that was the first easy out)

Funny thing this was one of the very rare scenarios in which external knowledge was somehow useful to solve this question.

Game theory is a ton of fun, but you definitely don't need outside information to answer GMAT verbal questions, and we recommend staying away from such info as you work through CR problems.

Here, for instance, (B) isn't really "off-topic." We're trying to explain the results of the study in the passage. Does (B) explain why public grazing land is in better shape than private grazing land?

Actually, it makes the results even more surprising -- if it's hard to measure how much damage an individual is doing to public land, then it seems like that individual wouldn't be afraid to do damage. No one's going to know the cost of the damage, right? Might as well trample public land all you want.

So, (B) definitely doesn't explain why public land is in better condition than private land, and you can eliminate (B).

I hope that helps!
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GMATNinja KarishmaB avigutman ThatDudeKnows in choice E we are told that more land was privately held - this works perfectly fine. If more land was held privately it implies that less public land was used and hence I can easily say this is the reason why common land was in good condition.

Posted from my mobile device

Well i think that you might have gone too far in assuming that the remaining common land is in better condition for sure...how can you tell this? You cannot infer that if less common land is available the remaining one is for sure in better condition than the private one. At least it would not be a sure thing and GMAT preys on this

Hi,

I have a doubt. Please help me out GMATNinja

The question says that 217 Million Acres of Common Land is compared to 433 Million Acres of Private Land.

Also, Statement E says that there is more privately held land than common land.

From these 2 statements, we can infer that it could be that we have only chosen a part of the total private land (only 433, out of maybe 1000 private total lands), or chosen a small part of the total common Land, and due to that, we've incorrectly arrived at the conclusion that "common lands are in a good condition" when it's not.

So, Option E helps us to explain the discrepancy right? Hardin says that the common lands are overused and they are, actually, overused.

Posted from my mobile device

To address option (E), let's start by looking at the question:


Notice that the question isn't asking us to explain the discrepancy exactly. Rather it's asking us to find something that would explain the study results IF the ranchers knew it to be true.

So does (E) fit the bill? Not exactly. If ranchers knew there was more privately than publicly held land, that knowledge wouldn't explain the results of the study.

But what if the study were wrong? What if the study examined 433 acres of private land that just happened to be in really bad shape? What if private lands as a whole were ACTUALLY in much better shape than public lands? While that could address the discrepancy, notice that (E) isn't telling us that exactly.

All (E) is telling us is that there is more privately held grazing land than publicly held grazing land. But that alone doesn't tell us that the study took non-representative samples of land. To draw that conclusion from (E) would require a big leap that we don't want to make.

Overall, (E) doesn't provide knowledge that, if held by the ranchers, would explain the study results. It also doesn't allow us to draw the conclusion that the study was misleading. For both of those reasons, we can eliminate (E).

I hope that helps!
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