To develop more accurate population forecasts, demographers

Hello Everyone!

Let's tackle this question, one issue at a time, and come up with the correct choice! First, let's take a quick look at the original question, and highlight any major differences between the options in orange:

To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

(A) have to know a great deal more than now about the social and economic
(B) have to know a great deal more than they do now about the social and economical
(C) would have to know a great deal more than they do now about the social and economical
(D) would have to know a great deal more than they do now about the social and economic
(E) would have to know a great deal more than now about the social and economic

After a quick glance over the options, we see a few places we can focus on:

1. have to know / would have to know
2. now / they do now
3. economic / economical

Let's start with #3 on our list: economic vs. economical. This is an easy way to eliminate 2-3 options because it's a common mistake we see on the GMAT:

economic = dealing with the economy
economical = inexpensive, cheap, thrifty, etc.

Since the sentence is talking about the economy, we can eliminate options B & C because they use the word "economical," which isn't the correct word for this sentence. That was quick, right?

Let's move up to #2 on the list: now vs. they do now. Here are the remaining sentences with the non-underlined parts added in to better catch any problems:

(A) To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

This is INCORRECT because it creates a non-parallel comparison. We are supposed to compare what demographers would have to know (knowledge) to what demographers know now (knowledge). This is comparing what demographers would have to know (knowledge) to now (time), which isn't parallel!
(This is also wrong because "have to know" isn't how to write a conditional statement. "Would have to know" is a condition, which would make this a conditional statement.)

(D) To develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the social and economic determinants of fertility.

This is CORRECT! It compares what demographers would have to know (knowledge) to what they know now (knowledge), which is parallel! It's also best to use "would have to know" to indicate this is a conditional statement, and it does that correctly!

(E) To develop more accurate population forecasts, demographers would have to know a great deal more than now about the social and economic determinants of fertility.

This is INCORRECT because it creates a non-parallel comparison. We are supposed to compare what demographers would have to know (knowledge) to what demographers know now (knowledge). This is comparing what demographers would have to know (knowledge) to now (time), which isn't parallel!

There you have it - option D is the correct choice! Even if you weren't confident on how to deal with conditional statements and verb tenses, you could still answer this question by focusing on parallel comparisons and proper word usage!


Don't study for the GMAT. Train for it.

To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

(A) have to know a great deal more than now about the social and economic
(B) have to know a great deal more than they do now about the social and economical
(C) would have to know a great deal more than they do now about the social and economical
(D) would have to know a great deal more than they do now about the social and economic
(E) would have to know a great deal more than now about the social and economic

The question tests the concept of Modifiers, Comparison, and Conditional sentences.

“To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.”
We can identify three points in the question that need to be examined.
When we do a vertical scan of the options, we see that two options begin with “have to know” and three options begin with “would have to know”.

Two options end in ‘economical’ and three options end in ‘economic’.

Two options have the phrase “more than now” and three options have the phrase “more than they do now”.

The choice between ‘economic’ and ‘economical’ is simple. The word ‘economic’ is the adjective form of the word ‘economy’ and is the better choice in this sentence because the sentence discusses the “social and ….. determinants of fertility. The word ‘economical’ means avoiding waste or extravagance. It doesn’t fit into the sentence.
On this basis, we can eliminate Options B and C.

To choose the best among Options A, D, and E, we can either use the rule of the Conditional sentence by choosing between the phrases ‘have to know’ and ‘would have to know’, or the rule of Comparison by choosing between the phrase “more than now’ and “more than they do now”.

Let us start with the rule of Comparison. The comparison should be between how much ‘demographers’ know now and how much the ‘demographers’ should know. The comparison will be complete only when the noun demographers is mentioned again or a pronoun is used to refer to them.
“demographers have to know a great deal more than now”

“demographers would have to know a great deal more than they do now”
It is only in the second construction that the comparison is complete.
On this basis, we can rule out Options A and E.

The Conditional sentence starts with ‘if’. However, in this sentence, the condition is conveyed through the prepositional phrase “To develop more accurate population forecasts”.
The construction of a conditional sentence is as follows:
If + subject + verb in the past tense, Subject + would/could + verb in the present tense.

If demographers wanted to develop more accurate population forecasts, they would have to know a great deal more than now about the social and economic determinants of fertility.

In this sentence too, that construction has to be maintained to make a proper conditional sentence. On this basis, Option A can be ruled out.

Therefore, Option D is the most appropriate option.

Jayanthi Kumar.

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that in order to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are related to social and economic factors.

Concepts tested here: Meaning + Tenses + Comparison

• The "would + simple present tense verb" construction is used to refer to hypothetical future actions and habitual actions in the past.
• Comparison must always be made between similar elements.
• The simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.

A: This answer choice incorrectly uses the simple present tense verb "have" to refer to a hypothetical future action; please remember, the "would + simple present tense verb" construction is used to refer to hypothetical future actions, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Further, Option A incorrectly compares "know" to "now"; please remember, a comparison must always be made between similar elements.

B: This answer choice alters the meaning of the sentence through the phrase "social and economical"; the use of "economical" incorrectly implies that to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are inexpensive; the intended meaning is that to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are related to economic matters. Further, Option B incorrectly uses the simple present tense verb "have" to refer to a hypothetical future action; please remember, the "would + simple present tense verb" construction is used to refer to hypothetical future actions, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.

C: This answer choice alters the meaning of the sentence through the phrase "social and economical"; the use of "economical" incorrectly implies that to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are inexpensive; the intended meaning is that to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are related to economic matters.

D: Correct. This answer choice uses the phrase "economic and social", conveying the intended meaning - that to develop more accurate population forecasts, demographers would have to know a great deal more than they do now about the determinants of fertility that are related to economic factors. Further, Option D correctly uses the "would + simple present tense verb ("have" in this sentence)" construction to refer to a hypothetical future action. Additionally, Option D correctly compares "know" with "do".

E: This answer choice incorrectly compares "know" to "now"; please remember, a comparison must always be made between similar elements.

Hence, D is the best answer choice.

All the best!
Experts' Global Team

D

AB: would establishes meaning better elim these two choices.

C: economical is inappropriate here. means inexpensive
E: same economical is inappropriate here. means inexpensive

please check out this link https://www.english-test.net/forum/ftopic4710.html

I'd go with (D).


This is future conditional, so I would eliminate (A) and (B) since they do not have "would".

I would eliminate (E) because of the faulty comparison. Comparing "know a great deal" and "now" is not apples to apples.

Your remaining choices are identical except for economic v. economical. Economical sounds weird to me in this context, so I'd go with (D).

OA is D.

Q41 - OG12:
Verb form; Logical predication
Th is sentence explains a hypothetical situation and therefore calls for a conditional—or contraryto- fact—construction, because in order to more accurately predict population, demographers would have to know more than they presently
know. A present-tense verb is required to describe the current state of demographers’ knowledge, and the comparison made by the sentence must be
between current and conditional knowledge, not between knowledge and time of knowing (now). A Wrong comparison—between knowledge and time (now); conditional verb is needed. B Conditional verb is needed; economical is the
wrong adjective. C Economical is the wrong adjective. D Correct. Conditional knowledge, indicated by would have to know, is correctly compared
to current knowledge. E Wrong comparison—between what demographers need to know and now.

The correct answer is D.

I will choose D

social and economic --> economic means related to finance ---> intended meaning

economical -thrifty ---> changes the meaning of the sentence --> making the fertility sound economical

A is clear OUT

D is left.

Hey Noburu,

Just to weigh in real quickly, we don't want "efficient" here. We want "economic", meaning "related to the economy" (economy meaning "wealth and resources" of a region or country). We want to know how economic (money-related) factors relate to fertility, etc.

-t

@ Bibli

Even a casual look at the choices will prove E as a wrong choice. There is no need to entertain any doubt about the inappropriate and absurd use of the word economical in the context. Rather, you must evaluate the topic first and eliminate unfit ones.

Secondly, look at the following post.

to-develop-more-accurate-population-forecasts-demographers-54658.html -- 18 posts

It contains at least 18 posts on these topics and there are at least another five posts that run up to another 30 posts . In spite of all these, do you still want a new discussion?. The same thing will hold good for your other posts, which have all been thoroughly discussed in the pages of this forum. Please remember you have to look before you leap and search before you script

Don't u think that "more accurate" and "accurate" are both conditional??
In both scenarios , It is a condition to achieve something..Can you give some more examples?

Ooh... now we're getting deep!

In the "pure" Anglo-Saxon system, the "conditional mood" does not exist because there is no inflected conditional mood. Idem for "future tense." What we call "future tense" and "conditional mood" are actually composed tenses from, respectively, the present and past forms of modal verbs.

However, neither of the two statements you proposed is actually a "conditional" statement. The second simply expresses factual belief about the future ("it will work"); the second refers to a future that is posterior to his belief but may well be anterior to the present moment; this is why we use the past tense form of "will" ("it would work"), also known as past posterior. The expression of his belief does not hinge on any condition.

In the case of this problem, however, we are dealing with a conditional statement, since the development of more accurate forecasts DOES depend on a condition (whether demographers can gather more information).

Whether the "if [present] then [present/future]" qualifies as a hypothetical conditional depends on the perspective and semantics. In this case it is clearly a conditional. The use of the present in the then-clause would make no sense, because while present tense can imply futurity in some cases, here we contrast this futurity to what they know now, so we would need another word (the "will") to "kick" it into the future.

Therefore, in answer to your question, it would not be correct to write: "To develop more accurate population forecasts, demographers have to know a great deal more than they do now about the social and economic determinants of fertility." It would be correct to write, "To develop more accurate population forecasts, demographers will have to know a great deal more than they do now about the social and economic determinants of fertility."

This does, of course, imply a slightly different angle than does the correct answer D. D suggests that this is idle, parlour game hypothesizing, whereas the sentence I just wrote reads as an instruction or a prescription.

i pick D here. this is a conditional sentence. one condition is to be fulfilled to develop more accurate population forecasts that demographers need to know more social and economic detrimental facts of fertility. So A and B are out. "economical" is just wrong here so C is out. in E comparison is not expressed properly. correct me if i am wrong.

regards

MGMAT says 'would' is used to express the future from the past's point of view.

Ex- The scientist believes that the machine would be wonderful

The above example is wrong as 'believes' is in present. If believes is replaced by 'believed' the ex becomes correct.

Now can someone explain why would is used here as the tense used in the question is simple present/present perfect.

Hi rajathpanta,

The scientist believes that the machine would be wonderful --> is incorrect because here we are mixing present with conditional.

Why is this so? because it is a rule. For conditionals there a few rules and you have to just remember them, there is not much to understand here. The rules on Conditionals are governed by set rules. MGMAT has explained the rules quite well, just make a note of them.

Consider this sentence: The scientist said that the machine would be wonderful. --> here "would" is expressing past as it is being used in the reported speech. The sentence is correct as per another rule on the usage of would.

The scientist believed that the machine would be wonderful - Correct usage, "would" expresses future from the past point of view.

Hope that helps,

Vercules

Hi rajathpanta,

Which question you are referring to. The main question of the post or your specific question. If it is your specific question, the please let me know which one.

Vercules

Hi rajathpanta,

In my last explanation I did not discuss hypothetical would, but a few rules related to would. I guess that you are confused because you are not able to find any conditional construct in the question above. The hypothetical would is used based on the context of the sentence. In almost all the questions which test standard conditional constructs "if then" constructions are used.

See the below question from OG12 which uses the conditional if x happened, then y would happen.

Q 67) Affording strategic proximity to the Strait of Gibraltar,.......

In the question above hypothetical conditional would is used. The sentence expresses a hypothetical situation, which needs a hypothetical conditional would. But, the incorrect answers are incorrect for different reasons, other than the use of would.

The question does not really test your knowledge on conditionals if you solve it by POC. The following question will also have the correct answer as (D). I have just made a change in option (D) ( "would have to" to "have to")

To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic detriments of fertility.

(A) have to know a great deal more than now about the social and economic
(B) have to know a great deal more than they do now about the social and economical
(C) would have to know a great deal more than they do now about the social and economical
(D) have to know a great deal more than they do now about the social and economic
(E) would have to know a great deal more than now about the social and economical


Correct choice is (D) because other options are wrong for clear grammatical and contextual errors; Although, "would have to know" will be better because the hypothetical situation is being discussed

The same conditional is tested in the following OG question;

Q 16) Retail sales rose 0.8 of 1 percent in August,
intensifying expectations that personal spending.....

I hope the above explanation helps,

Vercules

To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

A. have to know a great deal more than now about the social and economic - Since it is a hypothetical situation, a conditional clause must be used. Economic is correct
B. have to know a great deal more than they do now about the social and economical - Hypothetical Situation + Economical is wrong
C. would have to know a great deal more than they do now about the social and economical - Would Have is correct. Economical is wrong.
D. would have to know a great deal more than they do now about the social and economic - Correct
E. would have to know a great deal more than now about the social and economical - Illogical Comparison between knowledge and Time (Now). Economical is wrong

Economic - Is used to refer to general general economy
Economical is used for cost wise reference. E.g. Product X is economical (not economic)