1) Rognlie[1] pointed out that Piketty's central premise -- that the returns to capital are growing faster than the overall growth rate of the economy -- falls apart when you properly account for asset class and depreciation. The accelerating returns are specifically to real estate, while the returns to capital (excluding real estate) are flat.
2) Tyler Cowen pointed this out on his interview [2] with Piketty and Piketty essentially conceded the point.
Tyler implied therefore that the natural conclusion is Georgism[3]
[1] https://www.brookings.edu/bpea-articles/deciphering-the-fall...
[2] https://conversationswithtyler.com/episodes/thomas-piketty/
[3] http://gameofrent.com/content/is-land-a-big-deal#a-brief-rec...