* Demographers doing research for an international

[guest2]

Demographers doing research for an international economics newsletter claim that the average per capita income in the country of Kuptala is substantially lower than that in the country of Bahlton. They also claim, however, that whereas poverty is relatively rare in Kuptala, over half the population of Bahlton lives in extreme poverty. At least one of the demographers' claims must, therefore, be wrong.
The argument above is most vulnerable to which of the following criticisms?
(A) It rejects an empirical claim about the average per capita incomes in the two countries without making any attempt to discredit that claim by offering additional economic evidence.
(B) It treats the vague term "poverty" as though it had a precise and universally accepted meaning.
(C) It overlooks the possibility that the number of people in the two countries who live in poverty could be the same even though the percentages of the two populations that live in poverty differ markedly.
(D) It fails to show that wealth and poverty have the same social significance in Kuptala as in Bahlton.
(E) It does not consider the possibility that incomes in Kuptala, unlike those in Bahlton, might all be very close to the country's average per capita income.

The answer is 'E' but I don't understand why that is.
I narrowed the choices down to C and E through process of elimination, but Im not sure why E is the correct answer. Any help would be much appreciated.

Thanks in advance.

[manicchamp]

Answer is E because of the definitions used in the stem - average per capita income means total income/number of people

Hence if one country has lower average per cap income than another it does not mean that the income distribution in the country with lower average is as uneven as the country with a higher avg. income. Answer E clearly states that this fact about the lopsided income distribution.

Think of real life examples - Sweden/Norway say versus USA.

[RonPurewal]

the poster above me pretty much nailed it, but there are some important takeaways you can get from this one.

TAKEAWAY: the AVERAGE of a set of data doesn't tell you anything about the SPREAD or RANGE of those data.
think about this problem with the same critical mindset with which you'd analyze a QUANT problem about statistics. if i tell you that set A has a lower average than set B, this doesn't mean that the highest values in set A are lower than the highest values in set B, or even that most values in set A are lower than most values in set B.
for instance:
set A: 0, 0, 0, 0, 10 --> average = 2 (this could be bahlton)
set B: 1, 1, 1, 1, 1 --> average = 1 (this could be kuptala)
if the poverty line is, say, 0.5, this is a nice example of the issue here.

i trust that you'd be more likely to solve this one correctly if it were recast as a quant problem.

--

choice (c) is irrelevant, because absolute numbers don't have any bearing whatsoever on the argument. the argument deals only with proportions / percentages, so any objection to the argument must be based on premises that actually affect those percentages or proportions.

[resolehtmai]

Pardon me for reviving an old thread. i think i am getting addicted to mgmat forums.

I understand why E is the correct answer.
I dont get why B is so easily eliminated.
In fact I actually chose it as my final answer.

(B) It treats the vague term "poverty" as though it had a precise and universally accepted meaning.

If definition of poverty is vague and is different for different countries, its possible that one country X might have more poverty than other country Y, despite having more average per capita income. This weakens the conclusion that both claims are wrong.

-----------
Also in the below sentence of the argument,

average per capita income in the country of Kuptala is substantially lower than that in the country of Bahlton.

are we assuming that both incomes are expressed in similar currencies?

[RonPurewal]

Short answer:
(B) If the author is using a precise definition of poverty, that's not a "flaw" -- it helps the argument. In fact, it's actually a fundamental assumption! For the claims made about "poverty" to be meaningful, you need a consistent definition of "poverty".
In fact, for any statistic to be useful in an argument, that statistic must be defined uniformly throughout the argument.

This definition doesn't have to be "universally accepted" -- nor are the authors making any such assumption (= reason #2 why this choice is incorrect) -- but it has to be consistent.

[RonPurewal]

I don't think this problem is from the GMAT PREP software -- but I could be wrong. Still, let's table the discussion of this problem until a source is cited.

If this problem is from the GMAT PREP software, please post a screen shot.
If it's from another source, please post the source.

Thanks.