This is a really important point.
I'm currently reading The Rational Optimist (http://www.amazon.com/The-Rational-Optimist-Prosperity-Evolv...) which is about technology, innovation, and economic progress throughout history and one of his major points is that economies progress when people become more reliant on one another so they can focus on their specialty (ex., hire someone to do laundry because your time is most valuable coding). Economies in which people are self-sufficient are by definition less productive and innovative because there's less money flowing around and people are spending less time on the things they are comparatively better at.
It's a slow start but a fantastic read (and a challenging one for a person who likes to be self-sufficient).
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