The charts and data in Piketty's and Pinker's books miss elementary points of statistical significance.

Judge as of 2017-07-10. True: published critiques by statisticians or other qualified analysts document basic statistical-significance or inference errors (e.g. treating noisy trends as significant, ignoring fat tails or the sampling uncertainty of estimates) in the charts or data of both Piketty's 'Capital in the Twenty-First Century' and Pinker's 'The Better Angels of Our Nature', and these have not been convincingly rebutted. Mostly true: such errors are documented for both books but are contested, or are serious for one and minor for the other. Mixed: such errors are credibly documented for only one of the two books. Mostly false: critiques exist but mainly concern data or methods rather than statistical significance, or they are largely rebutted. False: there are no credible statistical-significance problems in either book, or the critiques have been shown to be wrong.

Set before the research began.

1. E1 Letters/Puzzle Significance (Royal Statistical Society), Oxford Academic · June 2016

   “Contrary to Cirillo and Taleb, we are perfectly aware that a stretch of time without a big war does not imply that a big war cannot happen.”

2. E2 Letters/Puzzle Significance (Royal Statistical Society), Oxford Academic · June 2016

   “devotes many pages to the power-law (fat-tailed) distribution of war magnitudes, and many more to the Poisson (temporally random) nature of inter-war intervals.”

3. E3 Bad maths in Piketty's capitalism critique? BBC News (Echo Chambers blog) · 28 May 2014

   “"Giles discovered a couple of clear errors and a number of adjustments that look questionable but have barely any impact on Piketty's charts."”

4. E4 The One Percent across Two Centuries: A Replication of Thomas Piketty's Data on the Concentration of Wealth in the United States Social Science History, Cambridge University Press · 4 December 2017

   “The heavily manipulated twentieth-century data for the top 1 percent share, the lack of empirical support for the top 10 percent share, the lack of clarity about the procedures used to harmonize and average the data, the insufficient documentation, and the spreadsheet errors are more than annoying.”

For Piketty's book, the evidence from before the judging date reports data errors and adjustments with barely any impact on the charts, not significance errors [E3]. For Pinker's book, the evidence shows only that one letter disputes the fat-tail critique by Cirillo and Taleb [E1][E2]. That letter does not show whether the critique was largely rebutted or still credibly stands, so the evidence cannot decide between the "mixed" and "mostly false" criteria.