The Rate of Return on Everything, 1870-2015 asks (and answers):
What is the aggregate real rate of return in the economy? Is it higher than the growth rate of the economy and, if so, by how much? Is there a tendency for returns to fall in the long-run? Which particular assets have the highest long-run returns?
And what’s key here is that if the rate of return is greater than the growth of the economy, inequality is exacerbated. Findings: over the past 150 years, the rate of return has been double the economic growth.