Google cofounder Sergey Brin has now spent more than nine figures combating California’s proposed wealth tax.
According to a filing from Friday, Brin donated an additional $20 million to Building a Better California, a PAC and political advocacy organization opposing the state’s billionaire tax and supporting other pro-business policies and housing and infrastructure affordability. He has now given a total of $102 million to the group.
Proposition 40, which will be on the ballot in November, would impose a one-time, 5% tax on California’s 200 billionaires, with 90% of the revenue from the proposed measure going toward the state’s health care program and 10% going toward education, food assistance, and administration. Brin, with a net worth of nearly $270 billion, could owe more than $13 billion as a result of the tax.
California, the most populous state, has become the epicenter of the conversation around the K-shaped economy, or the diverging fortunes of those with wealth and those without it. While the Golden State has a $4 trillion GDP, making its economy about the same size as the United Kingdom’s, it also has 18% of its residents living below the poverty line, the highest in the country, in part because of its high cost of living.
Billionaires push back against Prop 40
The ballot measure has caused an uproar among some of California’s wealthiest individuals such as former Google CEO Eric Schmidt and PayPal cofounder Peter Thiel, both of whom have donated to organizations against the measure. Brin compared the proposal to his socialist Soviet upbringing.
“I fled socialism with my family in 1979 and know the devastating, oppressive society it created in the Soviet Union. I don’t want California to end up in the same place,” he told the New York Times in a statement in April.
California Gov. Gavin Newsom has joined these tech billionaires in combating the measure, arguing the tax would hurt the state by eroding its tax base, ultimately reducing key revenue for social services.
“The fact is it actually will reduce investments in education,” Newsom said in a Bloomberg Businessweek interview earlier this year. “It will reduce investments in teachers and librarians, childcare. It will reduce investments in firefighting and police.”
The opposition to Prop 40 may in some ways be a self-fulfilling prophecy, as billionaires including Brin shift business entities out of California in favor of states without similar wealth taxes. Brin now lists Nevada as his residence, according to state records. Larry Page, who cofounded Google alongside Brin, has converted several of his assets out of California, including Koop, his family office, which was incorporated in Delaware in December 2025. Oceankind, an ocean science nonprofit founded by Page’s wife, Lucy Southworth, in 2018, was similarly incorporated in Delaware around the same time. Brin, for his own part, reportedly bought a $51 million home near Miami Beach in March.
