California billionaire tax could leave state with less revenue, Stanford study cautions
Updated on: October 19, 2026 / 10:55 PM EDT / CBS News
TL;DR
- Stanford economists estimate California's proposed billionaire wealth tax may generate significantly less revenue than projected due to billionaires moving out of the state.
- Seven billionaires have publicly moved, taking $540 billion in wealth, and more may have left quietly since the tax proposal.
- The tax could result in an estimated $30 billion in revenue, less than the $100 billion estimated by proponents.
- Future income tax losses from departing billionaires could exceed the wealth tax proceeds by approximately $39 billion.
- The Service Employees International Union-United Healthcare Workers West (SEIU-UHW), which introduced the measure, disputes the Stanford study's findings.
- Supporters of the tax, including Nobel laureates, argue it's fair for the ultra-wealthy to contribute to public spending and note California's continued attractiveness to venture funding.
- A recent poll indicates divided voter opinion on Proposition 40, with 46% in favor and 43% opposed.