Quote:
These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers are.
bb above gave a solid explanation. But this gives me the chance to talk about what is, in my opinion, one of the most difficult and frustrating concepts of the whole tests: ellipses. You might think of ellipses as the '...' , but here the 'ellipses' in a sentence are words that are allowed to be left out but are *implied by parallel structure.*
They are RAMPANT in comparisons. One of the trickiest aspects of SC comparisons is ellipses. To spot them you must ask yourself 'what words are left out? And is there *only one choice*?'
The sentence in question has an ellipses. The ellipses are included below in [brackets]:
These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers are [safe].
The 'safe' is implied, because we're saying 'this older group is safe, more safe than this younger group is safe.'
What if we drop the 'are?' No problem right? We could just throw the 'are' into the ellipses.
These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than the younger drivers [are safe].
Well... But wait. Who says, aside from human understanding, that in that sentence the ellipses aren't something like this:
These figures clearly show that the greater experience and developed habits of caution possessed by drivers in the 65-and-older group make them far safer behind the wheel than [the habits make them] the younger drivers.
(As if the habits of caution could make them 'safe' or make them 'into the younger drivers,' but here they happened to make the older drivers 'safe.')
You might be like, "But come on, that's crap." I hear you... Except the sentence, "The food coloring makes the eggs more blue than green." Has the same structure, and that
clearly means 'the food coloring makes the eggs more blue than [it makes them] green.'
(...if I were being hella pedantic, I could argue that the original sentence could read "The food coloring makes the eggs more blue than green [makes the eggs blue]," which is obviously wrong, so maybe the sentence should say "The food coloring makes the eggs more blue than it does green."
...But that doesn't seem right...
I don't know, man, truth is this why I *hate* ellipses!)
Regardless, the thing to always remember about GMAT SC is that it's not whether the meaning is clear to *you*, it's whether the meaning is clear 'objectively' (based on the rules of grammar, and allowing that language is still imperfect...) The meaning needs to be *in the structure*.
Now... I think they probably could have left the 'are' off in this case. But by including the 'are' they remove any ('objective') ambiguity from the sentence.
[My favorite sentence for ellipses is the infamous 'Halle's comet' SC question, by the way. Nightmare!]