gmat62 wrote:Because of the multiplier effect inherent in any unlimited-transaction economy, the spending of one dollar typically generates several times the gross income in such an economy than in a single- or limited-transaction economy.

A)typically generates several times the gross income in such an economy than
B)typically generates several times the gross income in such an economy than it would
C)typically generates several times as much gross income in such an economy as though
D)in such an economy typically generates several times as much gross income as the spending of one dollar would
E)in such an economy typically generates several times the gross income than

in option D is parallelism not faulty?

Hello! I'd better first try to indicate how to eliminate the other choices:
In A, B, and E you have "than" without a comparative adjective (more/greater/etc.). You can eliminate on this.
In C "as though" is wrong because it doesn't indicate a proper comparison when one thing is compared to another. The meaning is wrong. The correct usage of "as though":
We ran there as though [we had been] chased by ghosts.
In this example we are trying to give an impression that we were chased by ghosts. But in fact we weren't. You can say that this is "sort of" a comparison, but I wouldn't say that this is a proper one.
As to D: you don't have to have a perfect parallelism. Tenses are different in the first and he second halves of comparison, but they are justified.
"The spending of one dollar typically generates" is Present Simple, since it indeed does generate in reality some income.
"as the spending of one dollar would [generate]" - here we use "would" because we are talking about unreal situation, situation that exists only in our imagination.

thanks for your reply .
i want one clarification on this

Ron had once written: * if you have than/as + subject + HELPING VERB as the second half of a comparison, then you must have the SAME helping verb (perhaps in a different tense) in the first half of the comparison.

example 1: james can negotiate with salespeople more effectively than stephanie can.
example 2 i can run much faster than i could before my most recent knee operation. (note that "could" is the past tense of "can", so these are the same helping verb.)

is D not violating this stuff?

gmat62 wrote:thanks for your reply .
i want one clarification on this

Ron had once written: * if you have than/as + subject + HELPING VERB as the second half of a comparison, then you must have the SAME helping verb (perhaps in a different tense) in the first half of the comparison.

example 1: james can negotiate with salespeople more effectively than stephanie can.
example 2 i can run much faster than i could before my most recent knee operation. (note that "could" is the past tense of "can", so these are the same helping verb.)

is D not violating this stuff?

As fas as I'm concerned, Ron is the best GMAT expert. However, in this particular case I don't agree with him. I use Mitch's rule instead: https://www.beatthegmat.com/stadium-fill ... 99400.html
It can be applied in the same situations. The only difference is that you watch out for participles, not helping verbs.

The only difference is that you watch out for participles, not helping verbs.

can u please elaborate on this
Thanks

gmat62 wrote:

The only difference is that you watch out for participles, not helping verbs.

can u please elaborate on this
Thanks

You don't have to think about helping verbs at all. Instead, if you notice that a participle is omitted in the second half of a comparison, you should go to the first half and check whether it appeared there. This rule is applicable not only to comparisons, but also to any sentences in which a participle is missing.
In our case, no participles are omitted, so we don't have any problem.