Manufacturing jobs are disappearing but real manufacturing output has actually been steadily increasing over the last 50 years.

Yeah, imagine a production line hooked up directly to a web-based storefront where people are buying things to build. We're not far from it, and when this happens it probably won't be in China.

Very true, but still not a great place to be. Whether the boogeymen are robots or chinese workers, not having a market for manufacturing labor is a bad position for an economy.

Serious question: why?

I understand an economy that does not produce any of its own goods is in a jam -- it's an external critical dependency that can be wielded like a club against you. But if you have adequate internal production, what does it matter if it's done by humans, robots, or hyperintelligent cyborg orangutans? It may take a generation or so, but the people who would have been manufacturing labor will be absorbed into other markets -- or should be, as I understand it.

Should be? Why?

If "absorbed into other markets" means "wal-mart greeter", then that's bad. I'm all about efficiency and won't advocate make-work jobs, but if you don't have a base of demand in the form of a healthy middle class, it's hard to find people to buy the goods that you do manufacture.

I'm not sure how that affects the economy, but it certainly is a bad thing for a country. Not everyone can be a white-collar button-pusher; if no labor-based jobs exist anymore you'll make a significant portion of your citizens very unhappy