PT28.S1.Q10 - it is a principle of economics

aincao

http://7sage.com/lsat_explanations/lsat-28-section-1-question-10/
I don't understand how this is not A?

aincao

I feel like it may have something to do with switching the necessary and sufficient?

Matt1234567

Hi Aincao.

This is a principle application question. You're given a principle, and you're told to apply it to a scenario which conforms to the principle.

What is the principle?
A nation can experience economic growth ONLY when consumer confidence is balanced with a small amount of consumer scepticism.

from this, I drew the conditional as EG (experience economic growth) - - - > CCBS (consumer confidence balanced with small amounts of consumer scepticism).

Ok, from this condition above, we can only conclude 2 things: we can conclude /EG or we can conclude CCBS. We cannot conclude EG nor can we conclude /CCBS.

A says ) Any nation in which consumer confidence is balanced with a small amount of consumer skepticism will experience economic growth. This is our condition given backward, and notice how it concludes EG? We simply don't know what triggers EG.

D) is the right answer, because it kicks the contrapositive of the conditional statement and concludes /EG (no economic growth). D) says "any nation in which the prevailing attitude of consumers is exclusively confidence will not balance economic growth". This is exactly correct, because for it to experience economic growth, it need consumer confidence balanced with small amounts of consumer scepticism. To focus exclusively on consumer confidence means that it's not balanced, therefore, necessary condition failed, concluding /EG.

c.janson35

This is actually my favorite type of question because it is so easy to eliminate incorrect answers once you know what you are looking for:

The principle above is:

EEG-->CCBS

That is: if a nation experiences growth then it must be true that there is consumer confidence balanced with skepticism.

You are right in saying this is a necessary/sufficient issue. One thing we know is that we can never prove that a sufficient alone exists; so in this case, we can never prove that there is in fact economic growth. The only thing we can infer is in the case where there is growth, then it must be true that CCBS. Alternatively, by the contrapositive we could prove that there is NOT economic growth becaus that must occur when there is no CCBS.

/CCBS-->/EEG.

So, the only two things would could possibly conclude from the application of the principle is the existence of CCBS or /EEG.

My strategy is to go straight to the conclusion on these, and we are in luck! Every answer, except for D, concludes something about there in fact being economic growth, and because this is the sufficient in th original relationship, we cannot prove it. Therefore, eliminate A, B, C, and E.


D, as you can see, concludes that there is NOT economic growth, which we can prove through the contrapositive, and it checks out:

Exclusively confidence means that it is not the case that confidence is balanced with skepticism, so we have our sufficient trigger of /CCSB, there it must be true that /EEG.

Hope this helps!

aincao

Thanks Matt1234567 and c.janson35! That makes perfect sense now, looks like I need to study my argument forms a little more.