I am generally in favor of the policies that Gabriel Zucman proposes. Today, he and Emmanuel Saez wrote a guest essay (see also archive.ph version) for The NY Times arguing in favor of California’s proposed billionaire wealth tax. I think this would be a good tax. Zucman helped to create taxjusticenow.org in 2019, which shows historical tax rates for the US, and models the impact of wealth and other taxes on current tax rates; see the figure below.

I think taxjusticenow.org is a wonderful site. Even so, it only shows data up to 2018, and doesn’t show tax rates in any other countries. I contacted Zucman, and offered to pay for creation of a new site or page that has similar data to taxjusticenow.org, but was up-to-date, and included European countries. Zucman said it would require a specific large amount, and I agreed and paid in the form of a donation. Since then I have not received a single email from Zucman except when I asked for an update, when he pointed me towards a site focused on France that does not include any other countries or any historical data. In the same email he pointed out that he was ranked #15 on Politico’s “Class of 2026“; maybe he spends time promoting himself rather than creating the website. Rather than give more details I’ll summarize simply: Zucman did not delivered on what he said he’d do.