California's Billionaire Tax Vote: A Clash of Economic Forecasts and Political Power

Key points

• Proposition 40 imposes a one-time 5% tax on assets over $1 billion, payable over five years, to fund healthcare, education, and food assistance.
• UC Berkeley economists estimate the tax will raise $100 billion, while Hoover Institution economists estimate it will cost the state $39 billion due to lost income tax revenue from departing billionaires.
• Sergey Brin has contributed $102 million to 'Building a Better California,' a political organization opposing the tax and supporting counter-measures Propositions 41 and 42.
• The tax applies retroactively to California residents as of January 1, 2026, with some billionaires, including Larry Page and Sergey Brin, having relocated to Nevada to avoid it.
• Governor Gavin Newsom opposes the tax, arguing it will harm the state's economy, while progressives like Bernie Sanders and Ro Khanna support it as a necessary measure to address inequality and federal healthcare cuts.

Background

Proposition 40 is part of a broader national debate on taxing the superrich, following previous wealth tax proposals by Senators Elizabeth Warren and Bernie Sanders. The measure is also connected to Propositions 41 and 42, which aim to block the wealth tax by limiting state spending and banning retroactive taxation. The debate has intensified since the proposal was announced in late October 2025, with billionaires and political figures mobilizing significant resources to influence the outcome.

How outlets are covering it

Fox Business and Hoover Institution economists argue that Proposition 40 will drive wealthy residents out of California, reducing the state's tax base and costing billions in lost income tax revenue. They emphasize the retroactive nature of the tax and the potential for legal challenges. In contrast, UC Berkeley economists and proponents like Bernie Sanders argue that the tax will raise substantial revenue and address inequality, with minimal impact on income tax revenue. NPR highlights the stark contrast between these two economic analyses, noting that the debate is not just about California but about the future of wealth taxation in the U.S. and globally. Fortune and Politico provide additional context on the political maneuvering, with Sergey Brin's 'Building a Better California' organization playing a central role in the opposition campaign.

Why it matters

The outcome of Proposition 40 will have significant implications for California's economy and the broader national debate on wealth taxation. If passed, it could set a precedent for other states and the federal government to consider similar measures. If defeated, it could signal a shift in public opinion against wealth taxes and reinforce the power of billionaire donors in state politics. The measure also highlights the tension between progressive and conservative economic policies, with potential consequences for healthcare, education, and the state's tax base.

What to watch

California voters will cast their ballots on November 3 to decide the fate of Proposition 40. If the measure passes, the state will begin collecting the wealth tax over five years, with the revenue earmarked for healthcare, education, and food assistance. If it fails, the state will not collect the tax, and the debate on wealth taxation may shift to other states or the federal level. The outcome will also influence the political landscape in California, with 'Building a Better California' and other billionaire-backed organizations potentially continuing to shape state policy.