Tyler Cowen points out that there is a body of research studying wealth inequality, which apparently Piketty does not reference. This surprises me. After all, Paul Krugman (a very serious, straightforward, and trustworthy scholar, if there ever was one) points out that:
...if you think you’ve found an obvious hole, empirical or logical, in Piketty, you’re very probably wrong. He’s done his homework!This bears investigating, I think.