Brian Galle (UC Berkeley), David Gamage (University of Missouri), Emmanuel Saez (UC Berkeley), and Darien Shanske (UC Davis) have produced a memo attempting to address concerns over the proposed California Billionaire Tax Act:

This short memo addresses concerns that have been raised under the proposed California Billionaire Tax Act (CBTA or Act) about the valuation of “voting” or “special control” shares, particularly with regard to shares held in publicly traded companies. A misreading of the CBTA is circulating that claims that voting shares of all assets will be taxed in full regardless of their actual value. This is false, as shown by a straightforward reading about the provision relating to voting and special control shares in context.

For more TaxProf Blog coverage of the CBTA, see below:

• WSJ: The California Campaign to Introduce a First-of-Its-Kind Billionaire’s Tax(Nov. 14, 2025)
• Tax Notes and Shanske on California’s Proposed Billionaire’s Tax (Nov. 18, 2025)
• WSJ: Threat of California Billionaire Tax Draws Criticism from Ultrawealthy (Jan. 2, 2026)
• Washington Post: California Will Miss Billionaires When They’re Gone (Jan. 2, 2026)
• Galle, Gamage & Shanske: Correcting the Record: Responding to Some Legal Arguments About the 2026 Billionaire Tax Act (Jan. 9, 2026)
• NYT: Newsom Vows to Stop Proposed Billionaire Tax in California (Jan. 14, 2026)