About 200 years ago, the world started getting rich. Why?

"The simplest answer is that economic growth occurred only after the rate of technological innovation became highly sustained. Without sustained technological innovation, any one-off economic improvement will not lead to sustained growth."

I'm also thinking about the future here and even with a deceleration of innovation, as long as more countries start declining in birth rate, it still means better standard of living for the rest of us. Population growth can drive an economy, but it also eats up the money flowing out to people.

Of course there's also the very-unequitable distribution of wealth in societies to consider too.