Believe it or not, there is an article on wealth and inequality in the United States, with a reasonably good and accurately calibrated model. It is authored by Ana Castaneda, Javier Dıaz-Gimenez and Jose-Vıctor Rıos-Rull, and it was published in the Journal of Political Economy in 2003.
I find the conclusion a good place to start:
…we provide a theory of earnings and wealth inequality, based on the optimal choices of households with identical and standard preferences, that accounts for the U.S. earnings and wealth inequality almost exactly. We show that uninsured idiosyncratic earnings risk, retirement, altruism, and government transfers to retired households are essential ingredients of our theory, since they allow us to replicate the observed earnings to wealth ratios of both the rich and the poor households simultaneously. We also show that calibrating the earnings process directly is a must if we want our model economies to replicate the observed distributions of earnings and wealth in sufficient detail.
Here is the abstract:
We show that a theory of earnings and wealth inequality based on the optimal choices of ex-ante identical households who face uninsured idiosyncratic shocks to their endowments of efficiency labor units accounts for the U.S. earnings and wealth inequality almost exactly. Relative to previous work, we make three major changes to the way in which this basic theory is implemented:
(i) we mix the main features of the dynastic and the life-cycle abstractions, that is, we assume that our households are altruistic, and that they go through the life-cycle stages of working-age and of retirement;
(ii) we model explicitly some of the quantitative properties of the U.S. social security system; and
(iii) we calibrate our model economies to the Lorenz curves of U.S. earnings and wealth as reported by the 1992 Survey of Consumer Finances. Furthermore, our theory succeeds in accounting for the observed earnings and wealth inequality in spite of the disincentives created by the mildly progressive U.S. income and estate tax systems, that are additional explicit features of our model economies.
In other words we already have a theory which does quite well in explaining U.S. wealth inequality, and it isn’t based on the total centrality of a comparison of r and g, as you find in Piketty. And no one in the current debates is citing this piece, Piketty included. From the main results, note this:
We find that abolishing estate taxation brings about an increase in steady-state output of 0.35 percent and an increase in the steady-state stock of capital of 0.87 percent. Along every other dimension, the differences between the benchmark and the No EstateTax model economies are negligible. If anything, we find that abolishing estate taxation brings about a very small increase in wealth inequality [emphasis added]. Specifically, the Gini index of wealth increases from 0.79 to 0.80, and the share of total wealth owned by the top quintile increases from 81.97 percent to 82.33 percent.
We conjecture that the main reason that justifies these findings is that, given the demographics of our model economy, the role played by the estate tax rate in determining the after-tax rate of return of the economy is quantitatively very small.
I don’t hear this point brought up very much these days.
So much of the current Piketty debate is simply forgetting that…science exists and has already offered a wide range of insights on these topics, as well as having rendered some of the more extreme claims unlikely. In addition to what I offered Sunday, via Tony Smith here are a few additional links:
2. Aiyagari: http://www.minneapolisfed.org/research/WP/WP502.pdf
3. Heathcote et al: http://www.jonathanheathcote.com/HSV_AR.pdf