You guys are having a nice and friendly discussion around here. Allow me to join in and give you my take on the issue;

A fifty-year accord signed in 1994 by the United States, Canada, and Mexico dictated the reduction of tariffs that member nations had been permitted to levy on imports from other member nations.
A. dictated the reduction of tariffs that member nations had been permitted to levy---- You absolutely don't need the past perfect; "to permit" is not an "action verb".
B. dictated the tariff reduction that member nations had been levying-----------------> You don't levy a "tariff reduction", you do levy a tariff.
C. dictates the tariff reduction member nations have been permitted to levy----------->You don't levy a "tariff reduction", you do levy a tariff.
D. dictated the reduction of tariffs that member nations are permitted to levy----------> "dictated" is fine because of the date "1994" and "are permitted" is the correct use of the verb.
E. dictates the reduction of tariffs permitted for levying by member nations ------------> "permitted for levying" is clearly unacceptable

In general, avoid using the present perfect and the past perfect when you're dealing with non-action verbs such as "to permit", "to allow", etc... especially on the GMAT.

A similar SC question from the GMAT is shown below. Guess what the correct answer is.

A 1972 agreement between Canada and the United States reduced the amount of
phosphates that municipalities had been allowed to dump into the Great Lakes.

(A) reduced the amount of phosphates that municipalities had been allowed to dump
(B) reduced the phosphate amount that municipalities had been dumping
(C) reduces the phosphate amount municipalities have been allowed to dump
(D) reduced the amount of phosphates that municipalities are allowed to dump
(E) reduces the amount of phosphates allowed for dumping by municipalities

Got this one wrong but I see my mistake. I went too fast and thought that "reduction of tariffs" were a little wordy and went with the two that had "tariff reduction"

my bad.

A. dictated the reduction of tariffs that member nations had been permitted to levy - the accord is still active
B. dictated the tariff reduction that member nations had been levying - unidiomatic
C. dictates the tariff reduction member nations have been permitted to levy - that missing
D. dictated the reduction of tariffs that member nations are permitted to levy - CORRECT
E. dictates the reduction of tariffs permitted for levying by member nations - that missing

I think you have the wrong OA. Should be C. Please check.

present perfect is used for action which started in the past and continues into the present. So it should be dictates and "have been permitted".

If this fifty year accord which was signed in 1994 then it still holds - so still "dictates" rather than "dictated" which is past tense and over.

Thanks let me ping gmat instructors Sarai or Tommy.

As intimated above, I have some doubts about OA.

Firstly, reduction of tarrifs seemed wrong to me, as I thought it should be reduction in. So I eliminated other choices.

Secondly, the accord was signed in 1994 & is still valid, so we can use "dictates". I chose "C". Whats the source???
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I myself picked 'A' as the OA but below is the reasoning for why D is correct.

The sentence is talking of 2 different things.

The accord dictated reduction of tariffs

Tariffs that member nations are permitted to levy on imports

Between A and D.

A suggests that member nations had been permitted to levy tariffs [means member nations are not permitted to levy tariffs anymore] whereas
D says member nations are still permitted to levy tariffs [present tense]....which is correct

A fifty-year accord signed in 1994 by the United States, Canada, and Mexico dictated the reduction of tariffs that member nations had been permitted to levy on imports from other member nations.

A. dictated the reduction of tariffs that member nations had been permitted to levy

B. dictated the tariff reduction that member nations had been levying - this changes the meaning. The member nations are permitted to levy tariffs. This sentence says "member nations had been levying tariff reduction"....which is not the intended meaning.

C. dictates the tariff reduction member nations have been permitted to levy - this changes the meaning. The member nations are permitted to levy tariffs. This sentence says "member nations have been permitted to levy tariff reduction"....which is not the intended meaning.

D. dictated the reduction of tariffs that member nations are permitted to levy - CORRECT

E. dictates the reduction of tariffs permitted for levying by member nations - awkward

dictated is past tense. So basically you are saying that it was over sometime back and still going on.
"dictated" w/ present tense [are]. Did I miss something?

Compare with this SC. The use of past tense (violated) is correct in the OA since judge overturned the ban, so ban is history now. "ban violated the state laws" ---> is correct

Sentence is logical, there is no contradiction - State laws and ban couldn't coexist, so Judge was nice to let go the ban.

Nine months after the county banned jet skis and other water bikes
from the tranquil waters of Puget Sound, a judge overturned the ban on the
grounds of violating state laws for allowing the use of personal watercraft
on common waterways
A. of violating state laws for allowing
B. of their violating state laws to allow
C. that it violates state laws that allowed
D. that it violated state laws allowing
E. that state laws were being violated allowing

OA is D

Voila. Thanks for the explanations. I agree with the explanation for "levy".
You don't levy a "tariff reduction", you do levy a tariff.

A 1972 agreement between Canada and the United States reduced the amount of
phosphates that municipalities had been allowed to dump into the Great Lakes.

(A) reduced the amount of phosphates that municipalities had been allowed to dump
(B) reduced the phosphate amount that municipalities had been dumping
(C) reduces the phosphate amount municipalities have been allowed to dump
(D) reduced the amount of phosphates that municipalities are allowed to dump
(E) reduces the amount of phosphates allowed for dumping by municipalities

For the above question i'm optioning D.
A is wrong since it uses the past perfect "had been permitted". Past perfect is used to sequence two past actions. Guess if municipalities already dumped the wastes then they can't possibly reduce the amount of phosphates in the dumping. Its done, its over. Hence A OUT. D is correct.

I am quite ok with OA here.........here allowing is not the usual verb but functions as an Adverb ...allowing the(adjective) use(noun).....its a special case

I also guess it to be D ........thanks for the explanation

There is a great explanation from Stacey Koprince @ MGMAT in the following link regarding the OG question posted by Dakar Azu.

http://www.manhattangmat.com/forums/og-sc-62-t580.html

The accord was signed in the past, hence the tense of the verb 'dictate' should also be in the past. Eliminate C and E.
The member nations are still levying tariff. Hence ' are permitted to levy' is correct. IMO the answer is D.

actually I answered D but I took the risk since I realized it as 700+ question. answers of 700+ Qs look debatable away from basics. but it took 3 min.

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