They very often aren't, that's true. And in many cases, that's because real markets are not free markets; they are skewed by government intervention. The market for labor in the US, and indeed in most countries, certainly fits that description.

> As Keynes said, the market can stay irrational longer than you can stay solvent.

Yes, and he did his level best to make that prophecy come true by getting governments to intervene to keep markets irrational.

> poor people have more children than rich people

How is this relevant?