I’ve already written quite a bit about Piketty’s main thesis about growing income inequality, his suggestions for a remedy, and the praise his book has garnered.
But now comes the news that a Financial Times writer has accused Piketty of doing the math wrong:
Prof Piketty, 43, provides detailed sourcing for his estimates of wealth inequality in Europe and the US over the past 200 years. In his spreadsheets, however, there are transcription errors from the original sources and incorrect formulas. It also appears that some of the data are cherry-picked or constructed without an original source.
For example, once the FT cleaned up and simplified the data, the European numbers do not show any tendency towards rising wealth inequality after 1970. An independent specialist in measuring inequality shared the FT’s concerns.
Contacted by the FT, Prof Piketty said he had used “a very diverse and heterogeneous set of data sources … [on which] one needs to make a number of adjustments to the raw data sources.
“I have no doubt that my historical data series can be improved and will be improved in the future … but I would be very surprised if any of the substantive conclusion about the long-run evolution of wealth distributions was much affected by these improvements,” he said.
This is the sort of thing that’s often duked out between academics in the pages of arcane economics journals. But this particular fight’s gone out into the greater world, because of the huge and admiring press and political reception Piketty’s work has gotten.