File Under Fascinating

By James Kwak

A reader pointed me to “Instability and Concentration in the Distribution of Wealth,” a paper by Ricardo and Robert Fernholz (Vox summary here). It’s a pretty mathematical paper (and I’m not just talking about the usual multivariate regression here), and I didn’t make it through all the equations. But the basic idea is to come up with a model that might explain the high degree of income and wealth inequality we see in advanced economies and particularly in the United States, where 1 percent of the population holds 33 percent of all wealth.

What’s fascinating is that the model assumes that all households are identical with respect to patience (consumption decisions) and skill (earnings ability). Household outcomes differ solely because they have idiosyncratic investment opportunities—that is, they can’t invest in the market, only in things like privately-held businesses or unique pieces of real estate. Yet when you simulate the model, you see an increasing share of wealth finding its way into fewer and fewer hands:

As the authors emphasize, “it is luck alone – in the form of high realised random investment returns – that generates this extreme divergence.”  In the absence of redistribution, either explicit or implicit, this is the kind of society you end up with.

Obviously this isn’t a complete explanation of the high and increasing degree of inequality in American society today. People are not equal in their earning ability, for one. But you could view the variance in career outcomes—that is, from equivalent starting points, some people will just be luckier and earn more than others—as a type of the idiosyncratic risk that Fernholz and Fernholz focus on.

I think this is a useful antidote to the widespread belief that outcomes are solely due to skill, hard work, or some other “virtuous” attribute. Even if everyone starts off equal, you’re going to have a few big, big winners and a lot of losers. Because we want to find order and meaning in the universe, we like to think that success is deserved, but it almost always comes with a healthy serving of luck. Bear that in mind the next time you hear some gazillionaire hedge fund manager or corporate CEO insisting that he knows how the country ought to be run.