I made a stupid mistake of posting a conclusion before I had the whole analysis typed up or had looked up my references. I knew I would be called on it. I’ll appreciate any help with the <ref>'s. Also: I'm under Crocker's Rules, and criticism is welcome. So here goes nothi....
There's a theory out there that states that new inventions are combinations of old inventions <ref>. So if your hunter-gatherer tribe has knife-like rocks and sticks, just about the only thing you can invent is a spear. Fire + clay = pots. Little bones with holes + animal sinews + skins = needle => clothes. But if you were modern day's best chemist transported into the past, with all your knowledge intact, you'd be unlikely to make any aspirin. Why? Because the tools you need haven't been invented.
Instead of looking at what's projected to happen, consider what has been happening happened. With the increase in world population, the level technology and average standard of living have been going up.
I argue that more population => better technology => easier life => more population.
So what about the “unproductive” people? Those who “don't pull their own weight?” Those “living off of welfare, charity donations, etc?” Those who just barely survive off of subsistence living? They put a drain on world resources without adding anything back. Wouldn't the world be better off without them?
Suppose Omega made a backup copy of the Solar system. It created a perfect copy of everything else, but it only replicated 50% of humanity. Pick your favorite selection criterion for who will be copied. You will go to the copied world, and other you will live on as a zombie.
Suppose the people who work in sweatshops get copied. But subsistence farmers from the same regions don't. Then it's reasonable to predict that some people from sweatshops would quit their jobs and fill up the niche you left available. Fewer people would be supporting the developed world.
Historically, people used technology to solve population problems only when those problems became bad enough. Farming wasn't invented until there were too many hunter-gatherers. Industry was not invented until there were too many farmers. Sewers were not invented until there was a problem with urban pollution.
I'll skip the statistical argument1. If truly brilliant people (the likes of whom had invented the wheel, the steam engine and the computer) are 1 in a billion, then having more billions means having more of those people.
If you could choose whether your consciousness would go to Omega's backup world or stay on the original Earth, where would you choose? And if you chose the copied world, what selection criterion would you use to pick who would go with you?
Footnote1 : Statistics pop quiz (read: check my numbers, please). The world population is (~6,887,656,866). Let’s guess that “inventiveness” is distributed normally.I wouldn't be surprised if it were strongly correlated with IQ. How many people would you expect to find 6 standard deviations above the mean? IQ 190 for comparison. (upside down answer: 6.8). What about when the world population was 1 billion around 1800? (no calculators! just 1). We need to multiply 113 times to produce a person more than 7 standard deviations above the mean (IQ 205). The tail ends aren't necessarily this well-behaved, but then, given any distribution over the infinite competence axis, increasing the number of people would increase the number of people at each competence level.
EDIT: I rewrote this article. If you had managed to wade through the blabber I had before, my point stayed the same.