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.