Unless they are used as strictly temporary measures, rent-control ordi

WHAT CHOICE "MUST BE TRUE"
(A) munis place "limits on rent raise", thus landlords are allowed to raise rents;
(B) cannot be inferred;
(C) there are "several negative effects";
(E) cannot be inferred;

Ans (D) yes, now or in the future, there will be a shortage of units.

It took me 2 minutes to decide on my choice of (D).

(D) can be strongly supported by the texts above. "In many municipalities, ..., it is invariably the desire for short-term gain that guides those tenants in the exercise of that power." And the "short-term gain" is to implement rent control. It results in, among other things, a shortage of rental units over the long run. So, depending on the starting date of the rent control, in many municipalities there is now, or eventually will be, a shortage of rental units.

Other choices
(A) Contradicts the info that rent control still allow rent increase, albeit limited ones.
(B) Such ordinance will result in shortage of rental units, but shortage of rental units won't necessarily repeal the ordinance.
(C) Shortage is only one negative effect.
(E) In the long run, there will be a shortage of rental units. But as long as the rent control is in place, rental price upward is limited.

(D) In many municipalities there is now, or eventually will be, a shortage of rental units.

We can assume that rental units may decrease.
Answer:D

Unless they are used as strictly temporary measures, rent-control ordinances (municipal regulations placing limits on rent increases) have several negative effects for renters. One of these is that the controls will bring about a shortage of rental units. This disadvantage for renters occurs over the long run, but the advantage—smaller rent increases—occurs immediately. In many municipalities, specifically in all those where tenants of rent-control units have a secure hold on political power and can get rent-control ordinances enacted or repealed, it is invariably the desire for short-term gain that guides those tenants in the exercise of that power.

If the statements above are true, which one of the following can be properly inferred from them?

(A) It is impossible for landlords to raise rents when rent controls are in effect.

(B) In many municipalities rent-control ordinances are repealed as soon as shortages of rental unites arise.

(C) The only negative effect of tent control for renters is that it brings about a shortage of rental units.

(D) In many municipalities there is now, or eventually will be, a shortage of rental units.

(E) In the long term, a shortage of rental units will raise rents substantially.

B looks good since for short term people would be willingly take advantage of the ordinance i.e. people, naturally, would use benefits before the moment things balance out.

IMO Answer B.

This is a very good inference question and it preys upon those who take their 'real world' knowledge into the GMAT world.
I initially settled for (E) but was not confident with that answer, after reading the prompt for a second time I knew that (E) is the trap answer.

A general theme that you will see on inference questions is that the right answer is formulated as vaguely, and with no absolutes, as possible.
'... eventually will be' is your trigger word, would the sentence be phrased as 'There WILL be ...' it would be straight wrong.

Now, (E) displays one of the most favorite traps of the test maker. It's just a statement everybody, no matter if preparing for the GMAT or not, agrees upon. A shortgage of rental units will lead to a raise in rents, who could disagree with that? It's perfectly reasoned isn't it?
Well, it indeed is! But we are on the LSAT/GMAT inference section and nobody cares about what is common sense - we only care about information that is given in the prompt:

"Unless they are used as strictly temporary measures, rent-control ordinances (municipal regulations placing limits on rent increases) have several negative effects for renters. One of these is that the controls will bring about a shortage of rental units. This disadvantage for renters occurs over the long run"

Is there anywhere mentioned that the decrease in supply will raise the rents? No! Discard (E) and pick (D).

GOAL: Find a statement that MUST BE TRUE if the statements given are true. So, we need to do a POE here, trying to be extremely LITERAL when reading the argument and the answer choices, noticing words that may trick us: "ONE of these", "many", etc.

Now the POE:

(A) It is impossible for landlords to raise rents when rent controls are in effect.
We know that when rent controls are in effect, limits are placed on RENT INCREASES. This does not mean that landlords CAN NOT RAISE rents, but only means that the increases are limited. Eliminate (A).

(B) In many municipalities rent-control ordinances are repealed as soon as shortages of rental unites arise.
First, the argument only says that the enactment of the ordinance will lead to a shortage of rental units in the long-run. HOW do we know what will happen after the shortage, if it happens??? Moreover, if a shortage of rental units occurs, it may be caused by many factors, so we CAN NOT be sure that the tenants will power will REPEAL the ordinances to deal with the shortage at their favor.
Second, "as soon as", which means that "immediately after", is problematic. We CAN NOT be sure that the repeal of rent-control will happen immediately after shortages of rental units arise. Eliminate (B).

(C) The only negative effect of tent control for renters is that it brings about a shortage of rental units.
So this is why we need to be extremely LITERAL when solving CR questions, especially Inference/Must be true ones. The argument says that "ONE OF THESE [disadvantages] is that the controls will bring about a shortage of rental units" rather than that a shortage of rental units is the ONLY disadvantage/negative effect of the rent-control ordinances. Eliminate (C).

(D) In many municipalities there is now, or eventually will be, a shortage of rental units.
Because the tenants in many municipalities who possess power will INVARIABLY exercise that power for SHORT-TERM GAINS, they will want to ENACT the rent-control ordinances so that rent increases will be smaller at their favor (after all, they are the ones who have to pay for the rents). Here we not that the powerful tenants will have the ordinances enacted. Hence, according to the argument, the enactment of the rent-control ordinance will lead to a shortage of rental units OVER THE LONG RUN (so it must be true that the shortage happens now OR in the long-run.). Keep (D)

(E) In the long term, a shortage of rental units will raise rents substantially.
Again, we MUST NOT automatically assume the working of supply-demand law here. The argument only says that the enactment of the ordinance will lead to a shortage of rental units in the long-run. What will happen AFTER that, we don't know. We CAN NOT be sure that AFTER the shortage a decrease in rents will happen . Also, the adjective "SUBSTANTIAL" is problematic, HOW can we know that the decrease in rents, if it happens, will be SUBSTANTIAL??? Eliminate (E)

--> (D) is correct.

hi zhanbo,

not sure how D is inferrable

we are given what happens in general (that tenants influence the control ordinances and short term gain is what is guiding them)

but that does not mean that currently this is been done

although it's better of the rest, which is why this might be the answer

but it's not a sure sure inference