Larry H. Summers calls into question Saez and Zucmans research and the data they used in it at around 20 minutes. Gregory Mankiw calls them out at around 46:50 as being deceptive. Around 59 Saez sort of admits that his numbers are wrong and Larry goes on to tell him he is wrong and exactly how and why. Saez admits again that the book could be wrong around 1:01.
This is a bit like watch an economics soap and to a nerd like me it was an exciting thing to watch where we have two economists debunking another one. Regardless of the mathematical rigor missing from Saez's numbers the video is worth watching for the message that Summers and Mankiw present.
The economists Gabriel Zucman and Emmanuel Saez
let they're political leanings overcome their rationality as scientists
Instead of objectively reporting the latest findings from tax statistics, Zucman was placing his finger on the scale. He appeared to be bending his results to conform to the political narrative of Warren’s campaign, which he was also advising at the time. Through a series of highly opaque and empirically suspect adjustments, Zucman had artificially inflated the tax rate paid by the poorest earners while simultaneously suppressing the tax rate paid by the rich
Unfortunately trigger happy media believed them and the message went out in time for Warrens political agenda. The quote above is taken from here.
This sort of thing is extremely dangerous. The implications of modifying numbers to suit the political message while not new is not something you expect from professors winning awards. Saez got an honorary degree from Harvard and 2019 and the Bates Clark medal in 2009 and Zucman got the Bates Clark in April 2023.
The reason this is dangerous is that it calls into question all economists. We’re having a hard time right now with our democracy and having sensible policy created and followed through and it’s crap like this that allows populists to question and convince others that they shouldn’t be paying to much attention to science.