Over at the Washington Center for Equitable Growth: When I look at Thomas Piketty's big book, I see one thing that he failed to do that I think he really should have done. A large part of the book is about the contrast between "r", the rate of return on wealth, and "g" the growth rate of the economy. However, there are four different r's. And in his book he failed to distinguish between them.
The four different r's are:
The real interest rate at which metropolitan governments can borrow: call this r1.
The real interest rate that is the actual average return on wealthin the society and economy: call this r2.
The real interest rate that is the average risky net rate of accumulation--what capital receives, minus the risk of confiscation or destruction or taxation, plus appreciation in valuation multiples, minus what is spent in order to keep the world in the appropriate social position: call this r3.
A measure of the extent to which capital and wealth serve as an effective claim on income independent of how much capital there is--a standardized measure of what the society and economy's return on wealth would be at some standardized ratio of wealth to annual income: say, 4: call this ρ.
These four r's are very different animals. READ MOAR