Am enjoying this discussion. I just wiped out a long, ramble about 'everything' and decided the answer is still 42.
Fresh ramble.
The economy of the world will need a whole new paradigm soon. Either that or a huge plague or massive nuclear war that doesn't wipe out the human race. Even as we approach 1 Trillion humans on this planet, most are content with life. Yeah yeah, millions have little to nothing of consequence, but overall much of that can be attributed to local conditions. IN the developed world, most folks have what they need, and the whole economy tends to boil down to what do we all want.
Need is covered, want is not covered yet. Close but not yet.
Sort of boils down to what do the people of the world do? With machines doing more and more of the work, what will the people do? It will soon, give or take a dozen years, be a world being maintained by machines, not so much people.
Remember the Ludites?
IMHO, the world can not provide the number of jobs needed, and this will not improve. So what do the people do in the not so distant future? I envision masses upon masses of idle humans, fed and content for the most part, but with nothing to do other than sit idly at their screens absorbing data.
To the Republicans who believe that lower taxes will make more work....Prove that it has ever worked.