California Billionaires: Wealth, Taxes, and Wealth Tax Revenue Estimates

Jasper Boll (), Emmanuel Saez and Gabriel Zucman
Additional contact information
Jasper Boll: Paris School of Economics
Emmanuel Saez: University of California Berkeley
Gabriel Zucman: Paris School of Economics and UC Berkeley

No 45, Working Papers from EU Tax Observatory

Abstract: This paper documents the wealth of California’s billionaires and the taxes they pay. California billionaires’ wealth exceeds $2 trillion today, the equivalent of 50% of California’s GDP. It has grown 144% from 2023 to 2025, fueled by the AI boom. Over the longer run, the real wealth of California’s billionaire class—the 0.0002% richest households—has been multiplied by 38 from 1982 to 2026, while average real family income in California has about doubled. California billionaires pay about 0.2% of their wealth in California income tax ($3.2 billion/year), representing 2.4% of total California income tax revenue on average over 2023-2025. Using Securities and Exchange Commission data from Alphabet, Meta, Oracle, and Nvidia since 2004, we estimate the trajectory of wealth, income, and taxes paid by the top 4 California billionaires—Page, Brin, Zuckerberg, Ellison (through 2020), and Huang (since 2021)—focusing on their business wealth. This group alone holds nearly $1 trillion in business wealth, about 40% of total California billionaire wealth. For this group, wealth growth (+322% over 2023-2025) and low taxation (0.04% of wealth in annual California income tax) are more pronounced. The proposed one-off California billionaire tax of 5%, payable over 5 years, is both small relative to California billionaires’ wealth gains and large relative to the taxes they currently pay. We estimate that it could raise about $100 billion, with comparatively minor impacts on income tax revenue. Using empirical estimates of mobility responses to wealth taxation, we find that an annual wealth tax on California billionaires could raise substantial additional revenue even after accounting for income tax losses due to mobility.

Keywords: Wealth taxation; Wealth inequality; Taxation of high-net-worth individuals; Effective tax rates; Tax migration; Wealth concentration (search for similar items in EconPapers)
JEL-codes: D31 H21 H24 H26 (search for similar items in EconPapers)
Pages: 59 pages
Date: 2026-06
References: Add references at CitEc
Citations:

Downloads: (external link)
https://taxobservatory.world//www-site/uploads/202 ... evenue-Estimates.pdf Full working paper (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:dbp:wpaper:045

Access Statistics for this paper

More papers in Working Papers from EU Tax Observatory Contact information at EDIRC.
Bibliographic data for series maintained by Inga Chilashvili ().