It’s an educated guess, not the word of God. You don’t have to know it precisely to produce useful results. The entirety of physics is wrong, so what, it still allows us to build rockets, skyscrapers and computers.

The unit of analysis is firms, not individuals.

My interest, at the halfway point through The Famous Article, is whether the relative sizes of the firms (in employees) fit in there somewhere.

Money is used as a sort of analytic "low common denominator" in all of this work, but that seems a narrow window for viewing life in general.