Although improved efficiency in converting harvested trees into wood

Limiting to just A and B:

As an accepted custom, in two –part sentences, a pronoun first refers to the subject of the sentence and if there is no appropriate subject for the pronoun, however distantly the subject may be placed, then the given pronoun will try to stick to the nearest noun. We have to conjecture that.

In A, the subject is clearly the improved efficiency which befits the pronoun.

Now B: The subordinate clause is in active voice, while the main clause is in passive voice. How parallel is this structure?

If this exercise is from OG or GPREP, then let us take the OA. Otherwise we are entitled to contest the OA.

A is the clear choice.
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This is GMAT Prep's OE. I hope this will help some people. I generally do not like the OEs, so I would appreciate if people can discuss about the question.

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning of this sentence is key to solving the question; the intended meaning is that improved efficiency in converting harvested trees into wood products may reduce harvest rates, but this efficiency will stimulate demand by increasing supply and lowering prices because doing so will boost consumption.

Concepts tested here: Meaning + Modifiers

A: Correct. This answer choice uses the phrase "in converting harvested trees into wood products may reduce harvest rates", conveying the intended meaning - that improved efficiency in the process of converting harvested trees into wood products may reduce harvest rates. Further, Option A uses the clause "it (the efficiency) will stimulate demand by increasing supply and lowering prices"; the construction of this clause correctly implies that the improved efficiency in converting harvested trees into wood products will stimulate demand through the process of increasing supply and lowering prices. Additionally, Option A uses the phrase "thereby boosting"; the use of the "comma + present participle ("verb+ing" - "boosting" in this sentence)" construction conveys the intended meaning - that will stimulate demand by increasing supply and lowering prices, because, doing so boosts consumption; remember, the introduction of the present participle ("verb+ing"- “boosting” in this case) after comma generally leads to a cause-effect relationship.

B: This answer choice alters the meaning of the sentence through the clause "demand will be stimulated because of increasing supply and lowering prices"; the construction of this phrase incorrectly implies that increasing supply and lowering prices will stimulate demand; the intended meaning is that the improved efficiency in converting harvested trees into wood products will stimulate demand through the process of increasing supply and lowering prices. Further, Option B incorrectly modifies "increasing supply and lowering prices" with "which boosts consumption", incorrectly implying that increasing supply and lowering prices boost consumption; the intended meaning is that the improved efficiency will stimulate demand by increasing supply and lowering prices, because, doing so boosts consumption; remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma.

C: This answer choice alters the meaning of the sentence through the phrase "which boosts consumption"; the construction of this phrase incorrectly implies that improved efficiency in converting harvested trees into wood products will stimulate demand by increasing supply and lowering prices, and as a separate action, doing so boosts consumption; the intended meaning is that improved efficiency in converting harvested trees into wood products will stimulate demand by increasing supply and lowering prices, because, doing so boosts consumption.

D: This answer choice alters the meaning of the sentence through the phrase "of harvested trees being converted into wood products"; the construction of this phrase illogically implies that the improved efficiency of the harvested trees may reduce harvest rates; the intended meaning is that improved efficiency in the process of converting harvested trees into wood products may reduce harvest rates.

E: This answer choice alters the meaning of the sentence through the phrase "when harvested trees are converted"; the use of "when" illogically implies that improved efficiency that exists at the time when harvested trees are converted into wood products may reduce harvest rates; the intended meaning is that improved efficiency in the process of converting harvested trees into wood products may reduce harvest rates; remember, "when" is used to refer to a point in time. Moreover, Option E further alters the meaning of the sentence through the clause "demand will be stimulated because of increasing supply and lowering prices"; the construction of this phrase incorrectly implies that increasing supply and lowering prices will stimulate demand; the intended meaning is that the improved efficiency in converting harvested trees into wood products will stimulate demand through the process of increasing supply and lowering prices. Additionally, Option E incorrectly modifies "increasing supply and lowering prices" with "which boosts consumption", incorrectly implying that increasing supply and lowering prices boost consumption; the intended meaning is that the improved efficiency will increase supply and lower prices, and as a result, boost consumption; remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma.

Hence, A is the best answer choice.

To understand the concept of "Comma + Present Participle for Cause-Effect" on GMAT, you may want to watch the following video (~3 minutes):



To understand the concept of "Which, Who, Whose, and Where" on GMAT, you may want to watch the following video (~1 minute):



All the best!
Experts' Global Team
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A seems fine.
B - "because of" seems unnecessary

C and D - IMO "of converting" somehow is less attractive than "in converting". Someone else think so too? There are other things wrong with D as well.

E - totally out.

Hi ishancrazee,

In this question C, D "efficiency of converting harvested trees" and "efficiency of harvested trees" are idiomatically incorrect. "When" in (E) is also not preferred because its use will imply of the efficiency at a particular time "when" harvested trees are converted into wood products.

A. in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices,
thereby boosting.

(A) correctly uses the participle "boosting" to modify the previous clause, meaning that "boosting" is a result of "increasing supply and lowering prices". Moreover "in converting" usage is better than those in other answer choices.

B. In converting harvested trees into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and
lowering prices, which boost.

In (B) if you see the last part "which boost" it means that the verb "boost" should agree with a plural subject, which in this case seems to be "increasing supply and lowering prices". On the other hand, one might say "which" modifies the noun closest to it i.e. prices; this usage will be more preferred. But, even if we take this usage into consideration, we will change the meaning of the original sentence, which intends to say that both "increasing supply and lowering prices" are boosting consumption.

C. Of converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices,
which boosts.

Incorrect as explained above

D. Of harvested trees being converted into wood products may reduce harvest rates, it will stimulate demand, because it will increase supply
and lower prices, thereby boosting.

Incorrect as explained above

E. When harvested trees are converted into wood products may reduce harvest rates, demand will be stimulated because of increasing supply
and lowering prices, which boost.

Incorrect as explained above.

Hope this helps,

Vercules
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Option A) - Looks good
Although improved efficiency in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, thereby boosting consumption.
it replaces improved efficiency and "thereby boosting" - a verbing modifier correctly expresses the idea that act of stimulating demand by increasing supply and lowering prices will boost the consumption.

Option B) In converting harvested trees into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and
lowering prices, which boost.
which is a relative pronoun and closes noun is prices. The meaning stands as lowering prices boost consumption - Meaning changes - Incorrect.

Option C) efficiency in converting is the correct usage and which boost is the same error as B has.

Option D) efficiency in converting is the correct usage. Any segment of the sentence if it is inside the comma pair is non essential part of the sentence and can be taken out.
If we take out the non essential part of sentence, the sentence becomes as following:
it will stimulate demand, thereby boosting -> which changes the meaning. The cause and effect is removed.

Option E) Very awkward and wordy. "When harvested trees" - Incorrect.

Although improved efficiency in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, thereby boosting consumption.

Meaning : The improved efficiency may reduce harvest rates but it will stimulate demand by increasing supply and lowering prices . The increasing supply and lowering of prices will result into boosting consumption.

So there is a cause and effect relationship between "increasing supply and lowering of prices" -> boosting consumption.

here the sentence structure of Clause + Comma + Verb+ing modifier (or participle modifier) is apt as the modifier modifies the previous clause by answering how or what resulted. Hence the usage of the modifier -> boosting is correct.

For example.
Sunita mesmerized the crowd, singing a popular song.

Now the phrase "singing a popular song" explains how "Sunita mesmerized the crowd" so the phrase "singing a popular song" modifies the previous clause.
And secondly, the action of singing attaches to the subject of the previous clause and should make sense. So in the above example, singing make sense with the subject of the previous clause "Sunita" so both the rules are satisfied for Verv+ing modifier.

So applying the same theory, the action of "boosting" attaches to the subject of the previous clause "efficiency " so the efficiency is finally boosting the consumption and that make perfect sense.

A. in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices,
thereby boosting.
As per above analysis, the option A) looks good.

B. In converting harvested trees into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and
lowering prices, which boost.

which is a relative pronoun and can refer to a noun only. Here we require a cause and effect relation where we need to modify the previous clause.

C. Of converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices,
which boosts.

which is a relative pronoun and can refer to a noun only. Here we require a cause and effect relation where we need to modify the previous clause.

D. Of harvested trees being converted into wood products may reduce harvest rates, it will stimulate demand, because it will increase supply
and lower prices, thereby boosting.

being -> is used when the action is continuous . In this example, the action of converting is not ongoing process as we make the above statement and hence the usage of "being" is wrong.
As per the original choice -> How the efficiency will stimulate demand , by increasing supply and lowering prices. But in this option the reason for stimulating demand is that efficient will increase supply and lower prices which is a meaning change (which is not required as meaning of option A is not wrong). As per option A) it seems to be a simultaneous actions, but in option D) demand will increase because of the some future action.

E. When harvested trees are converted into wood products may reduce harvest rates, demand will be stimulated because of increasing supply
and lowering prices, which boost.

When cannot be used for condition. When is used for a specific time period.
which cannot refer to the whole clause and cannot modify the whole clause.

In converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices,
Before concluding that a pronoun has reference problems, we have to see whether possible contenders tally in number with the pronoun. In this case, 'it' cannot refer either to trees or products or rates, as all of them are plural and the only eligible contender is 'efficiency'. This is one of the clearest cases of pronoun reference

B, on the contrary, has a serious modifier issue. We start with a modifier" Although in converting ….' and then what is followed is not the noun that does the action of converting. It is some obscure 'demand". Therefore, B essentially suffers a misplaced modification. On top of it, the passive voice main clause makes it murkier.
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aragonn GMATNinja GMATNinja2 sudarshan22 broall hazelnut Vyshak generis

Can any of the experts please take this one up?
I am stuck between A and B.

PriyankaPalit7

The differences are subtle at first glance.

The A/B distinction is hard to describe with the typical code words and splits.

If I were to focus on anything in particular, it would be COMMA + WHICH
That construction creates unclear logic with missing links. Those problems lead to unclear meaning in B.

(I wish the correct answer were positioned as option E. After reading option A, a person is NOT confused. Immediately after reading A, a person reads B, which seems clear. It isn't. )

The COMMA + ___ING construction, on the other hand, creates direct, complete, and clear logic. Meaning in option A is clear.

Separating grammar and meaning in these sentences is not a great idea because ultimately meaning decides the issue.

We can, however, use noticeably different constructions in the options to tease out the meaning.

• SUBJECT + BY v. NO SUBJECT + BECAUSE OF

Both by and because of are indicators of causal agency.

Stimulated (increased) demand is a result of P (increased supply) and Q (lower prices)

What causes P and Q?

Option A has an answer: improved efficiency.
The pronoun IT = improved efficiency

Improved efficiency creates an increase in supply, and that increase in supply drives down prices.
(Then lower prices create more demand, and more demand leads to more consumption.)

Option A uses one short, direct preposition and a known subject in the main clause.

Option B has no answer.

In option B, P and Q are direct objects of the compound proposition "because of."

Objects of prepositions are not very active, and they certainly cannot be subjects of another clause.

This issue might not be problematic if we were dealing with a simple conjunction such as BUT.

We are not dealing with a simple construction. This question tests a different construction, namely,
Although X, Y

In option B, we do not know what causes two events. Further, no clear link TO "boost[ed] consumption" exists.

Do P and Q logically do two things?
Do P and Q cause stimulated demand (as the prepositions indicate) AND
boost consumption?

Causality is much clearer in option A than in option B because option A is not missing a link.

• PARALLELISM

Option A: Although X, Y
Although improved efficiency may decrease the number of harvested trees (X), improved efficiency will [also] stimulate demand and thereby boost consumption (Y)

Option B Although X, Y in option B is
Although improved efficiency may decrease the number of harvested trees, (X), demand will be stimulated by . . . ., which boosts consumption (Y)

Despite the fact that both efficiency and demand are nouns, option B shows superficial parallelism compared to option A.
Although connotes contrast.

Option A conveys that ONE agent causes two contrasting and disparate results.
Option B conveys that ONE agent causes one result, and ANOTHER agent causes a contrasting and disparate result.

Two agents would be fine if we knew:
1) what created two agents that then created demand;
and 2) what led to a boost in consumption. That is, we have a

Problem: the second agent in B, stimulated demand, is caused by two other events, both of which seem to come out of nowhere.

Your mind may make the connection between improved efficiency and increased supply,
but option B contains no actual language from which to infer such a connection.

If we had more material, we could probably infer that more efficient conversion causes increased supply.
As the sentence stands, however, we cannot infer that improved efficiency creates increased supply.

Plausible scenario: demand for wood products stays the same whether the conversion process is more efficient or not
People do not need more wood products.

Plausible scenario: demand for wood products skyrockets because wood products that were very expensive got much cheaper because efficiency increased the supply of wood products
People DO need more wood products but could not afford those products

Two plausible but contradictory scenarios from the same fact pattern? Ambiguity. Option B is unclear.

Option A is better than Option B in the idiomatic construction Although X, Y

• COMMA + ___ ING: absolutely correct. COMMA + which: almost certainly not correct.

COMMA + ---ING
In order to express the result of events or information described in a previous clause (or phrase), COMMA + ___ING is very effective and economical.

COMMA + ___ING (some people use COMMA + verbING)
-- is an adverbial modifier that uses a participle. COMMA + ____ING can modify an entire clause or phrase
-- in this instance, both thereby and boosting indicate the effect of a preceding cause:

BECAUSE improved efficiency will stimulate demand (because efficiency increases supply and thus reduces prices), improved efficiency will also increase consumption

Stripped: efficiency increases demand, thereby boosting consumption

The adverbial modifier in the form of a participial phrase is a very effective way to link one clause to subsequent events.
Correct: The tornado touched down for three minutes, destroying everything in its path.

COMMA + WHICH boost consumption
This construction is typically not very good for conveying complex causality.

If the noun or nouns that precede "which" are direct causes of whatever comes after which, the construction will usually work, but it is not as effective as a participial phrase.

COMMA + WHICH
-- is a relative clause. Almost always, COMMA WHICH must refer to an immediately preceding noun or nouns, or a noun phrase
-- boost is plural verb, indicating that the antecedent of which is plural.

This construction creates a hot mess. What is the antecedent of "which"?
Does that antecedent fit in logically?
Does THAT antecedent boost consumption?
Logically, how do we get TO the boosted consumption?

(1) If the antecedent of which is lower prices, then only lower prices boost consumption (if "which" modifies only the nearest noun).
The two other causal agents (supply and demand) in the main clause can't simply be eliminated or ignored.

(2) If the antecedent of which is the process in which increasing supply leads to lowering prices, then we lose "demand."

(3) If we allow "which" to "hop over" BOTH prepositional objects in order to reach "demand," we have a subject/verb error.

In (1), we cannot simply eliminate those other two causal agents (supply and demand); lower prices are part of a causal chain that includes those two agents.

In (2), we cannot simply eliminate "demand."
-- Demand is the result of greater supply and lower prices
-- Stimulated demand MAY be the direct cause of boosted consumption. (see the logical chain below).

This question is hard.

Option A is far better than Option B.

ANSWER A

I hope that analysis helps. (Whew!)

I have separated causality from grammar cues in an artificial way because it is really difficult to explain the chain of events, the logical sequence.
The meaning of the sentence is tied directly to that sequence.
We have nested agents of change (the "Russian doll" scenario).

The logical line of causation is direct.
The words and phrasing do not seem to be direct.

MEANING depends on CLARITY and COMPLETENESS of logic
If you can analyze the meaning of the two sentences, the correct answer becomes obvious.

The sentence means that
-- more efficient conversion of trees to wood products may
reduce the number of trees that must be chopped down,
but
the improved efficiency will lead to
an increase in supply, which leads to
a decrease in price, which leads to
an increase in demand, which finally leads to
an increase in consumption.

Overall meaning: Although improved efficiency may lead to a Good Thing, improved efficiency [also] will lead to a Bad Thing.

CAUSALITY

The final outcome is boosted (increased) consumption
That outcome tacitly leads companies to chop down more trees, a result that nullifies the saving of trees created by improved efficiency.

What directly causes increased consumption?
Option A: Stimulated demand.
Option B: unclear

-- Reduced prices do not cause increased consumption.
-- Increased supply does not cause increased consumption.
-- Those two events create greater demand.

More accurately, increased supply results in reduced prices, and reduced prices result in stimulated demand.


For example, reduced prices would not cause an increase in supply. Greater supply comes first.
Think about the matter from a profiteer's perspective.
Why would I produce MORE wood products in a market in which I get paid LESS for them?

We do not have to be economists. The logic of the prepositions by and because of is
EFFECT (demand) by CAUSE (greater supply that leads to lower prices)
EFFECT (demand) because of CAUSE (greater supply that leads to lower prices)

We cannot jump from improved efficiency to stimulated demand (higher demand). Other causal agents intervene.

Option A contains this causal sequence:
Improved efficiency → increased supply → reduced prices → stimulated (higher) demand → boosted (higher) consumption

Improved efficiency (1) increases supply (2).
Increased supply (2) decreases prices (3).
Lower prices (3) stimulate demand (4).
Higher demand (4) boosts (increases) consumption (5).

In option A
The word order in the causal sequence of the main clause is 1 → 4 → 2→ 3, →5
The logical order 1→2→3→4→5, however, is intact.
The meaning of the sentence is also intact.
Although improved efficiency may reduce rates (X), improved efficiency will also stimulate demand by __ and ___, increasing consumption (Y)

Option B contains this causal sequence:
Increasing supply (1) causes a lowering of prices. (2)
Lower prices (2) create stimulated demand. (3)
SOMETHING unclear causes boosted consumption (4)

The word order in the main clause is 3 → 1→2,[??] →4
The logical order is not intact.
The meaning of the sentence has changed.
Although improved efficiency may reduce rates (X), demand will be stimulated by __ and __, and something will boost consumption. (Y)

ANSWER A
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Awesome analysis generis

I have one small additional query.
If coma+verb-ing modifier presents the results of a preceding clause,
is not thereby redundant in (A) ?

I would place much more emphasis on parallelism issue than
a. voice (active/ passive) as pointed out
by daagh above (contrast is much more clear with a single subject: improved efficiency)
b. Usage of coma+ verb-ing modifier vs logical antecedent of which, although
plural verb boost did help me to know I am referring to plural nouns.

I always have nightmares with usage of that/ which and use below rule:

• When that/which is used as a relative pronoun, it can refer only to the singular noun
• When that/which is used as a noun modifier, it can refer to singular/ plural nouns.

Whenever in doubt, I can use the verb that follows that / which as you did in above and then
look into meaning/ casuality (aptly conveyed by coma+verb-ing modifier) in the sentence.
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EducationAisle

In option A, doesn't "thereby reducing" modify the subject of the sentence "it" which refers to "improved efficiency" and its verb? However the "thereby reducing" should modify "increasing supply and lowering prices". Please respond to this question in detail since I am confused and it seems I have some knowledge gap regarding comma + verb-ing modifiers

Thanks!

Well, thereby reducing will indeed modify the subject of the sentence it, which refers to improved efficiency (not sure what you mean by and its verb; a pronoun cannot refer to a verb; by its very definition, a pronoun can only refer to a noun/noun-phrase).


Well, a case can definitely be made that improved efficiency boosts consumption (by increasing supply and lowering prices). So, this is in fact a very classical use of present perfect.
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Hi!

Does someone know the correct use of "efficiency in" and "efficiency of" ?

Thanks!

Although improved efficiency in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by:
-increasing supply and
-lowering prices
,thereby boosting consumption

The ‘it’ in this sentence is referring to the singular ‘improved efficiency’

(A) in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, thereby boosting (Correct)

(B) in converting harvested trees into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and lowering prices, which boost

(C) of converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, which boosts
-‘of’ is the incorrect preposition

(D) of harvested trees being converted into wood products may reduce harvest rates, it will stimulate demand, because it will increase supply and lower prices, thereby boosting
-meaning changes: suggests that the improved efficiency belongs to harvested trees being converted

(E) when harvested trees are converted into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and lowering prices, which boost
-disconnect b/w the efficiency and the conversion of harvested trees into wood products arises due to the introduction of the relative pronoun ‘when’
-the prepositions ‘because of’ are incorrect and make it seem like the increasing supply and lowering prices are already ongoing when in fact they represent the means by which demand will be stimulated
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Hello Lionila,

I will be glad to help.

Let us analyze these two expressions in a very simplistic way.

We put our effort "in doing" something. For example, The teachers have put a lot of effort in setting the question papers.

However, we measure the efficiency "of something". For example, The efficiency of the software has been proven by its popularity.

In this official sentence, we see the first usage. Hence, the usage of the phrase "efficiency in" is correct.


Hope this helps.
Thanks.
Shraddha
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A. Correct
B. Does not show the connection that 'improved efficiency causes increase supply ...'
C. Wrong idiom 'efficiency of'
D Same as C
E. 'efficiency when' changes meaning

EducationAisle

What's the problem with B? I was confused between A and B and I ended up choosing B. Is it because of which? Please explain.

Although improved efficiency in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, thereby boosting consumption.


(A) in converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, thereby boosting

(B) in converting harvested trees into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and lowering prices, which boost ( "which" is ambiguous, it incorrectly refers back to prices, distorting the meaning the scentence intended to convey)

(C) of converting harvested trees into wood products may reduce harvest rates, it will stimulate demand by increasing supply and lowering prices, which boosts （idiom issue of should be followed by noun, instead of clause, eliminate immediately)

(D) of harvested trees being converted into wood products may reduce harvest rates, it will stimulate demand, because it will increase supply and lower prices, thereby boosting ("improved efficiency" is supposed to be used to modify a process, not the harvested trees,eliminate immediately)

(E) when harvested trees are converted into wood products may reduce harvest rates, demand will be stimulated because of increasing supply and lowering prices, which boost ("when" incorrectly refers to efficiency, eliminate immediately)