Global ecological problems reduce to the problem of balancing supply a

Question

Global ecological problems reduce to the problem of balancing supply and demand. Supply is strictly confined by the earth’s limitations. Demand, however, is essentially unlimited, as there are no limits on the potential demands made by humans. The natural tendency for there to be an imbalance between demand and sustainable supply is the source of these global problems. Therefore, any solutions require reducing current human demand.

Which one of the following is an assumption on which the argument depends?

(A) Supply and demand tend to balance themselves in the long run.
(B) It is possible to determine the limitations of the earth’s sustainable supply.
(C) Actual human demand exceeds the earth’s sustainable supply.
(D) It is never possible to achieve a balance between the environmental supply and human demand.
(E) Human consumption does not decrease the environmental supply.

KarishmaB · Accepted Answer

Problems arise because of gap between supply and demand. 
Supply is limited by Earth's resources
Demand is virtually infinite. 
This imbalance leads to problems.

Conclusion: Reduce current demand.

We are concluding that we need to reduce current demand to solve our problems. 
So we are assuming that currently, demand is more than supply (that is why we need to reduce it) to achieve the balance. 
Hence, (C) is correct.

(A) Supply and demand tend to balance themselves in the long run.

We are not assuming that they WILL balance in the long run. We are looking for solutions that will help us balance them.

(B) It is possible to determine the limitations of the earth’s sustainable supply.

We are given that there are limitations of the earth’s sustainable supply. The supply is limited but the demand is infinite. Whether we can actually determine the limitations of the Earth's supply (whatever that means) or not, it doesn't matter. We know that limitations exist.

(C) Actual human demand exceeds the earth’s sustainable supply.

Correct. We have assumed this to say that we must reduce demand. We know there is an imbalance. We know that supply is limited but demand is infinite. But those are the characters of our supply and demand. We are not given that currently, the demand exceeds the sustainable supply. To conclude that we must reduce demand, we are assuming that currently, demand does exceed supply. That is why we need to reduce demand.

(D) It is never possible to achieve a balance between the environmental supply and human demand.

We are looking for solutions to achieve a balance so apparently, we do believe that it is possible to achieve.

(E) Human consumption does not decrease the environmental supply.

The discussion is on sustainable supply, the supply that can be maintained. Human demand, if higher, will create problems so supply will be affected. 
We are not assuming that supply does not decrease.

Answer (C)

Bunuel · Answer

EXPLANATION FROM Fox LSAT

The question asks for “an assumption on which the argument depends,” i.e., a Necessary Assumption. The trick to answering Necessary Assumption questions is to pick the answer that must be true in order for the argument to make any sense. In other words, pick the answer that,  if untrue , would cause the argument to fail.

Here, the argument says that the Earth’s supply is fixed, but the demand of greedy humans is essentially unlimited. Makes sense so far. The conclusion then says that “any solutions require reducing current human demand.” This seems fairly reasonable… I can’t see a huge hole here. We’ll have to just go through the answer choices and pick the one that seems like it is necessary support for the argument.

A) Um, no. If this were true, actually, then the argument probably wouldn’t make any sense because the argument wants us to reduce demand rather than wait for things to “balance themselves.” I don’t see how this answer choice provides any support, let alone  necessary  support, for the argument.

B) I don’t see why we need to be able to “determine,” i.e. calculate, the limitations of the Earth’s supply. Why is that relevant? I think B could be untrue and the argument would still make sense. If B is untrue then it is impossible to calculate the limitations of supply. So what? That doesn’t ruin the argument. The conclusion that “any solutions require reducing demand” would still make sense. So B isn’t necessary.

C) Oh, this could be it. If this is untrue, it becomes “actual human demand does not exceed Earth’s sustainable supply.” And if  that  is the case, then why would we need to “reduce current demand”? Couldn’t we just level it off at the current rate and be OK? I like this answer.

D) What? If this is true then we might as well just give up. This doesn’t support the argument at all.

E) This is just plain weird. “Demand doesn’t reduce supply”? That makes no sense to me. I think this is just a bunch of words from the argument mixed up into a batch of nonsense.

Answer C, if untrue, would destroy the argument. Therefore C is necessary support for the argument, and is our answer

rickysinghk11 · Answer

IMO C.

What is important here is to notice the difference between "potential demand" and "Actual demand".
C fills out the crack.

AkshdeepS · Answer

Which one of the following is an assumption on which the argument depends?

Conclusion : Any solutions require reducing current human demand.

Why? First point comes in mind is due to limited supply and excessive demand.  
 
(A) Supply and demand tend to balance themselves in the long run.

If this is the case then there is no need to discuss the conclusion.

(B) It is possible to determine the limitations of the earth’s sustainable supply.

Possibility of determining limitations of earth's sustainable supply is irrelevant.

(C) Actual human demand exceeds the earth’s sustainable supply.

Correct : If this is negated, the conclusion will not hold true. We can't do anything about supply so try to reduce demand. 
 
(D) It is never possible to achieve a balance between the environmental supply and human demand.

Same as A.

(E) Human consumption does not decrease the environmental supply.

If this is true then it is good. No purpose of writing such conclusion.

celo700 · Answer

Conclusion: Solution for the global problems caused by an imbalance between demand and sustainable supply is to reduce  current  human demand. 
But the premise talks about  potential  demands.
So, there is the logical gap. Author assumes that just like potential demands are unlimited, current human demands are also unlimited and exceed the supply. Only then the argument holds and that is why, we should reduce the current human demand.

Which one of the following is an assumption on which the argument depends?

Nothing of that sort is mentioned in the passage. Even if they do balance, is supply increased or demand decreased? We, cannot deduce and hence won't help the conclusion.

If it is possible to determine the limitations of supply, then how is it helping the conclusion that demand should be decreased?

Correct

If anything, this statement is a weakner.

It does not matter whether we can increase or decrease the supply. Conclusion is about reducing demand and this statement does not address that issue.

gmat1393 · Answer

Hi  AndrewN

Though I understand that C is the right answer, can you please help me in understanding why D is an incorrect choice?

The negation of D will be It is sometimes possible to achieve a balance between the environmental supply and human demand.
 and this weakens the conclusion Therefore, any solutions require reducing current human demand.

AndrewN · Answer

Hello,  gmat1393 . The problem with (D) is that the conclusion mentions  solutions  to correcting the imbalance between environmental supply and human demand. The conclusion thus assumes that it is indeed  possible to achieve a balance . Your negation would be accurate. The answer in front of us is the opposite of what we want. (Another hint: be wary of overreaching language—e.g. never, always, must, cannot. Most of the time, such language appears in trap answers.)

I hope that helps clarify the issue. Thank you for calling my attention to the question.

- Andrew

Bunuel · Answer

EXPLANATION FROM POWER PREP

This stimulus provides a series of statements involving the application of the law of supply and demand to global ecology. Global ecological problems are created when there is an imbalance between demand and sustainable supply, and global supply is inherently limited, but potential global demand is not. Based on these premises, the author concludes that any solution to global ecological problems would require reducing current human demand:

Premise: Global ecological problems are created by an imbalance between demand and sustainable supply.

Premise: Global supply is limited, but  potential  global demand is not.

Conclusion: The only way to solve the natural tendency toward imbalance is to reduce  current  global demand.

Note the leap from a premise about the  potential  global demand to a conclusion about  current  global demand. The author apparently equates these two, with the  assumption  that current global demand causes the same tendency toward imbalance. As we seek an answer choice that addresses this issue, one way to verify the correct assumption is to apply the Assumption Negation Technique. When the negated version of an answer choice weakens (or destroys) the argument in the stimulus, we know that the given answer choice reflects an assumption on which the argument relies.

Answer choice (A): The stimulus discusses the natural tendency toward imbalance between demand and sustainable supply, which is the problem for which the author is suggesting a solution, so this assertion may run counter to the information provided in the stimulus. Even if supply and demand were to balance themselves out in the “long run,” it is unclear how long this might take. It is the general tendency toward imbalance that causes the problems the author seeks to solve.

If we apply the assumption negation technique to check our work, this is the negated version of this answer choice:

“Supply and demand don’t tend to balance themselves out in the long run.”

Since this would not weaken or destroy the argument in the stimulus, this answer choice cannot reflect an assumption on which the author’s argument depends.

Answer choice (B): We don’t need to be able to determine the precise limitations on the earth’s sustainable supply in order for that supply to be outpaced by human demand, so this cannot be an assumption on which this argument relies. To check our work, we can apply the Assumption Negation technique and note whether the negated version of the answer choice would have any effect on the strength of the author’s argument:

“It is not possible to determine the limitations of the earth’s sustainable supply.”

Even if this were impossible, this would not necessarily hamper our ability to deplete the supply completely and this would not affect the conclusion that human demand must be lowered as a part of any solution to the ecological problem, so this cannot be an assumption on which the argument is based.

Answer choice (C): This is the correct answer choice.  For the argument’s conclusion to be logically drawn, we must assume that there is not only  potential  for demand to outpace supply—actual current demand must exceed the earth’s supply for there to be an imbalance which requires a solution. Applying the Assumption Negation technique to the answer choice would yield the following:

“Human demand does not exceed supply.”

If this were the case, then lowering human demand as called for in the conclusion would not necessarily be so vital. Because the negated answer choice weakens the conclusion in the stimulus, this must be an assumption required by the argument.

Answer choice (D): If it were never possible to achieve a balance between environmental supply and human demand, there would be no long term solution to the global ecological problem, presuming that actual current demand were to outpace global supply. Since the stimulus discusses prospects for finding a solution, this answer choice cannot be an assumption on which the author’s argument relies. To check our work, we can apply the assumption negation technique by logically negating this answer choice:

“It is sometimes possible to achieve a balance between the environmental supply and human demand.”

Since this would not weaken the argument in the stimulus in any way, this answer choice cannot reflect an assumption on which the conclusion of the stimulus relies.

Answer choice (E): The argument in the stimulus is based in part on the idea that there are no limits on potential human demands. If these demands did not decrease the earth’s supply, the problem that the author is looking to solve would not really exist, so this cannot be an assumption on which the argument relies. To check our work, we can again apply the assumption negation technique, to arrive at the following negated version of this answer choice:

“Human consumption does decrease environmental supply.”

As we can see, the negated version of this answer choice has no weakening effect on the argument in the stimulus, so this cannot be an assumption on which the argument relies.

VerbalBot · Answer

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Global ecological problems reduce to the problem of balancing supply a

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