I'd agree that risk capacity (or element of ruin, as it's known in gambling circles) is a big factor in rising inequality. But there are many other advantages that the wealthy enjoy that may also explain the divergence. The wealthy can borrow money at much more favorable rates, they can meet minimum investment thresholds in ventures or funds that provide higher rates of return, they benefit from economies of scale in large businesses, the list goes on and on.

And just as there is no one major cause, there is no one major solution, like a wealth tax. Rather, we need to overhaul much of our financial and business regulation to favor decentralization. Limits on corporate and real estate ownership, corporate board participation, and business advertising would all go a long way toward reinvigorating small business and creating a healthier, less homogenized economy.