Some general thoughts on the controversy over Piketty and his data.
1. We have no evidence he intentionally falsified data. There are problems and anomalies and questions about cherry-picking and the like, so he definitely has some ‘splainin’ to do. However, this is not about fraud. It’s not Bellesiles. Yet.
2. Economists make adjustments to data all the time, especially when dealing with old, incomplete, and inconsistent data sets. The question is whether they are justified or just done to make the data consistent with your priors. Piketty has a potential problem here and we need to see what his response is. His first round reply in the Financial Times was a whole bunch of nothing.
3. If there are real data problems (and they aren’t about intentional falsification), then we need to consider how fatal those are to his argument. With Reinhart and Rogoff, the data errors didn’t change the overall argument, but did toss out the 90% threshold which wasn’t the central point anyway. So let’s see how this plays out.
The revelations of the last few days are yet more reasons (along with other errors of theory and history) to treat the book skeptically, but they are not indications of academic fraud, nor is it clear how fatal they are to his argument. Yet. Those juries are still out, but the preponderance of the evidence is starting to mount.
(Cross posted at Coordination Problem)