Note that my calculations are sensitive to (a) progress in technology scaling linearly with two-heads-are-better-than-one as Michael Kremer postulates, and (b) that the world be capable of supporting 3 billion people at near-Malthusian pre-industrial levels of productivity without generating substantial and irreversible resource depletion. Buy those and it follows. But you have to buy those first...
]]>May I purchase the ebook during that three-day window?
Yours,
Brad DeLong
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