Washington Post columnist Robert J. Samuelson wrote on 29 Dec 2004 about some fundamental changes that loom large for the US (and "developed" world) economy. He argues that we've had a good run, for the past half-century or more --- but several of the key curves are about to bend, maybe fold. Inspired by Samuelson's article, my big-picture synopsis of our situation:
What does all this add up to? Note that, unlike the litany of downers, technological progress can continue indefinitely. (Athough if that last bullet above doesn't turn around soon, maybe not.) And "natural resources" can continue to be discovered, invented, and exploited. (Again with some big footnotes, particularly concerning agriculture.) But those possibly-positives don't outweigh all the emergent negatives during the next several decades.
Bottom line: I predict tight times for young people who expect to live better than their parents without working nearly as hard ... and for old people who expect to retire in comfort by taxing the next generation.