TAXES: Europe tried wealth taxes. Most gave up.

Economists Emmanuel Saez and Gabriel Zucman estimate the Sanders proposal would raise $4.4 trillion over a decade. Competing estimates from the Tax Foundation and the American Enterprise Institute project significantly lower totals of $3.3 trillion and $2.3 trillion, respectively.

Saez and Zucman’s estimate for Warren’s proposal has more than doubled since the legislation was first introduced in 2021, which the economists attribute largely to the rapid growth in billionaire wealth during that period.

Zucman has estimated that U.S. billionaires pay an effective tax rate of about 23%, though Magness disputed that figure, arguing broader accounting methods place the rate closer to 40%. A 2025 paper by IRS economist David Splinter estimated effective tax rates as high as 45% for top earners.

Wealth taxes have largely disappeared across Europe. Twelve European countries imposed wealth taxes in the 1990s, but only Spain, Norway and Switzerland still maintain them today.

“In practice, these measures have almost never delivered on their promised tax revenue,” Magness told The Center Square.

According to Magness, countries including Austria, France, Sweden, Finland and Denmark repealed their wealth taxes between 1994 and 2018 because of low revenue yields and concerns that high-net-worth residents would move assets or relocate abroad.

We’ll see if California voters figure this stuff out before or after they drive out even more wealthy taxpayers.