Comment by imtringued

If you accept that the economy can be in disequilibrium, then it is very easy to see how this happens.

Rich people learn a habit that makes them consume less than their investment returns. The difference is reinvested, resulting in a net increase of their equity. Even if you say they spend 90% of their returns on consumption, the last 10% still grow in absolute terms. Since returns are paid proportionally based on the quantity of equity, you can clearly see that money is allocated from where it has high marginal utility to places where it has low marginal utility.

Of course this leads to a contradiction. If money is held by people who have a low marginal utility for consumption, why would investments pay high returns? Your equity is the latent demand that your investments need to pay you the returns in the first place. You'd increasingly be paying yourself. That is equivalent to investing into something that yields a 0% return which in turn is equivalent to doing nothing.