California’s proposed billionaire wealth tax could “kickstart a movement” that spreads to other states, the federal government, and even other countries, according to a group of Nobel laureates backing the measure.
The initiative, known as Proposition 40, would impose a 5% tax on the net worth of California residents above $1 billion. If passed, it would be the first wealth tax of its kind in the United States.
In an open letter released this week, more than 20 Nobel laureates in economics — including Joseph Stiglitz, Paul Krugman, and Esther Duflo — argued that the measure would not only raise billions for public services but also serve as a model for other jurisdictions.
“The concentration of wealth in the hands of a few is not just an economic problem; it is a democratic one,” the letter states. “California has the opportunity to lead.”
The Details
Proposition 40 would apply to approximately 200 billionaires who live in California. The tax would be calculated annually based on net worth, including stocks, real estate, and other assets. The revenue — estimated at $10 billion to $15 billion per year — would be directed toward public education, healthcare, and affordable housing.
The measure has drawn fierce opposition from business groups and wealthy individuals who argue it would drive billionaires out of the state. Elon Musk, who left California for Texas in 2020, has called the proposal “insane.”
Supporters counter that the tax is narrowly targeted and that most billionaires would stay. They point to polling showing broad public support for higher taxes on the ultra-wealthy.
The Movement
The Nobel laureates’ letter is part of a broader push to replicate California’s model elsewhere. Similar proposals have been introduced in Washington, New York, and Illinois. Internationally, lawmakers in France, Spain, and Brazil have expressed interest.
The Biden administration had proposed a federal billionaire minimum income tax, though it failed to pass Congress. Progressive lawmakers say a federal version could be revived if California succeeds.
“The California initiative is a proof of concept,” said Gabriel Zucman, an economist at the University of California, Berkeley, and a leading advocate for wealth taxes. “Once it passes, the dam breaks.”
The Opposition
Opponents argue the tax would be legally dubious, economically harmful, and difficult to enforce. They say wealth is not the same as income, and that taxing unrealized gains would force billionaires to sell assets to pay the tax.
“It’s a recipe for capital flight,” said Jon Coupal of the Howard Jarvis Taxpayers Association. “California’s economy is already losing high earners. This will make it worse.
The opposition has spent tens of millions of dollars on advertising, warning that the tax will hit middle-class Californians by driving up costs and reducing investment.
The Bottom Line
California’s Proposition 40 would impose a 5% tax on billionaires’ net worth, raising $10 billion to $15 billion annually for public services. Nobel laureates say it could spark a global movement for wealth taxes. Opponents argue it will drive billionaires out and harm the economy. The measure will be decided by voters in November.
My opinion
California’s billionaire tax is not just a revenue measure. It is a test of whether the wealthiest Americans can be taxed like everyone else. For decades, the answer has been no. Billionaires pay lower effective tax rates than their secretaries. They borrow against their assets instead of selling them. They move to Florida or Texas when a state gets too demanding.
Proposition 40 would change that calculation. Not because it would raise an enormous amount of money — $10 billion to $15 billion is a rounding error in a state with a $300 billion budget — but because it would establish a principle: that extreme wealth is not sacred.
The opposition’s argument is predictable. They say it will drive billionaires out. Maybe some will leave. But the history of tax policy suggests that most people stay where they have roots, businesses, and communities. The fear of capital flight has been used to block progressive taxation for generations. It is time to test whether that fear is real.
The Nobel laureates are right. If California passes this, other states will follow. If it fails, the movement dies. The stakes are larger than one state, one tax, one election.
