Americans are fleeing.
California’s long-running debate over taxes and the cost of doing business is intensifying as voters weigh Proposition 40, a November ballot measure that would impose a new one-time tax on some of the state’s wealthiest residents.
Recent polling has shown a closely divided electorate, while business and real estate leaders warn that uncertainty surrounding the proposal could influence investment decisions, luxury home sales and the willingness of high-net-worth residents to remain in California.
The debate comes at a time when many Californians are already concerned about housing expenses, inflation, borrowing costs and the overall cost of living.
For voters, Proposition 40 is quickly becoming about more than billionaires. It has opened a much broader discussion over how California raises revenue — and whether additional taxes could eventually affect businesses, jobs and the state economy.
What Is California Proposition 40?
Proposition 40 will appear on California’s November 3, 2026 general election ballot.
The measure would impose a one-time tax equal to 5% of qualifying wealth on certain California taxpayers whose covered assets exceed $1 billion.
Covered assets can include businesses, securities, artwork, collectibles and intellectual property. Real estate and certain pension and retirement assets generally would be excluded.
The measure applies to qualifying billionaires who were California residents on January 1, 2026. The tax would become due in 2027, although taxpayers could spread their payments over five years at an additional cost.
According to California’s official voter information, 90% of the revenue would be directed toward health care. The remaining 10% would support food assistance or education-related programs.
Billions in Revenue — But Potential Long-Term Tradeoffs
California’s nonpartisan Legislative Analyst’s Office estimates that Proposition 40 could temporarily generate tens of billions of dollars over several years.
That potential windfall is a major argument for supporters.
But the state’s own fiscal analysis also acknowledges another possibility.
Some billionaires could respond to the tax by restructuring their finances, reducing taxable income or leaving California.
If that happens, the Legislative Analyst estimates California could experience an ongoing reduction of less than $1 billion per year in income-tax revenue collected from billionaires.
That uncertainty has become a central issue in the campaign.
Supporters believe the temporary revenue could provide substantial funding for health care and other public programs.
Critics question whether collecting a large one-time payment is worth the possibility of losing recurring tax revenue in later years.
Real Estate Leader Warns of Growing Tax Fatigue
Luxury real estate executive Aaron Kirman is among those raising concerns.
Kirman, founder and CEO of Christie’s International Real Estate Southern California, has argued that another major tax could make California less attractive to wealthy residents, entrepreneurs and investors.
He says the uncertainty surrounding Proposition 40 is adding another layer of hesitation to a luxury real estate market already dealing with high mortgage rates, inflation and broader economic uncertainty.
According to Kirman, some affluent buyers and sellers are delaying decisions while they wait to see how California’s tax environment develops.
His broader concern is that wealthy residents do not operate in isolation.
High-net-worth individuals frequently own companies, employ workers, purchase services and make investments that circulate through the wider economy.
Kirman argues that when those residents relocate, the potential consequences can reach beyond the luxury housing market and into restaurants, retail, construction and other local businesses.
Whether Proposition 40 would produce departures on a large scale remains uncertain. California’s official fiscal analysis says taxpayers could alter their behavior in response to the tax but notes that the size of those effects is difficult to predict.
The Debate Is Bigger Than Billionaires
Proposition 40 directly targets an extremely small portion of California’s population.
But the political debate surrounding it reaches much further.
Some taxpayers worry that measures initially aimed at the wealthiest residents could eventually become models for broader taxes.
Supporters of Proposition 40 argue that the concern is misplaced because the measure specifically targets billionaire-level wealth.
They contend that people with extraordinarily large fortunes can contribute more toward public services without imposing additional taxes on middle-income families.
Opponents raise a different concern: wealthy taxpayers and businesses often have greater freedom to relocate than ordinary workers.
That creates a difficult balancing act for policymakers.
Higher taxes can raise money for government programs, but tax policy can also influence where businesses invest and where individuals choose to establish residency.
California’s Business Climate Under the Microscope
California remains an economic powerhouse.
It is home to major technology companies, entertainment studios, financial firms, agricultural businesses and some of the most valuable real estate markets in the United States.
The state’s enormous economy gives California advantages few other states can match.
At the same time, California has spent years debating whether taxes, regulations and high operating costs are making it harder to retain businesses and residents.
Proposition 40 has brought that argument back into the spotlight.
Supporters believe California’s concentration of wealth means the state can raise substantial revenue from a relatively small number of taxpayers.
Opponents believe repeatedly targeting highly mobile taxpayers could eventually weaken the tax base California relies upon to finance government services.
The Legislative Analyst’s Office effectively acknowledges both sides of that equation: the measure is expected to produce a large temporary revenue increase, while also carrying the possibility of lower recurring income-tax collections.
Los Angeles Mansion Tax Becomes Part of the Argument
Kirman has also pointed to Los Angeles’ Measure ULA as a warning about unintended economic consequences.
Measure ULA created an additional tax on high-value real estate transfers in Los Angeles, with revenue intended to support affordable housing and homelessness programs.
Critics in the real estate industry say the tax has discouraged some large transactions and complicated development economics.
Supporters argue that Los Angeles needs significant new funding to address housing affordability and homelessness.
Proposition 40 involves a different type of tax, but the argument surrounding both measures is similar.
How aggressively can government tax wealth and expensive assets before taxpayers change their behavior?
There is no simple answer.
Taxes can produce revenue for public programs, while investors and property owners can sometimes respond by delaying transactions, changing investment strategies or relocating.
That tension is now becoming one of the defining questions surrounding Proposition 40.
Where the Proposition 40 Money Would Go
Unlike a general tax increase, Proposition 40 includes specific rules governing how the money would be used.
Under the official ballot language:
- 90% of Proposition 40 revenue would be allocated to health care.
- 10% would support food assistance or education-related programs.
- The tax would apply to qualifying covered assets exceeding the billionaire threshold.
- Real estate and some retirement assets generally would be excluded.
- The measure is structured as a one-time tax, rather than a recurring annual wealth tax.
Those provisions are important because they give voters a clearer picture of what the measure would actually do.
The California Secretary of State lists SEIU United Healthcare Workers West among Proposition 40’s supporters. Opponents listed in the official voter guide include the California Primary Care Association, California School Boards Association and California Taxpayers Association.
That unusual mix underscores how the proposal does not divide neatly along a single interest-group line.
California Voters Face a Larger Question About Taxes
The November vote ultimately comes down to competing economic priorities.
Supporters see Proposition 40 as an opportunity to raise billions of dollars for health care and other programs while concentrating the cost on taxpayers with extraordinary levels of wealth.
Opponents are focused on the potential long-term consequences of encouraging wealthy residents, investors and business owners to move money — or themselves — elsewhere.
The state’s own fiscal analysts say both outcomes deserve consideration.
California could receive tens of billions of dollars in temporary revenue if Proposition 40 passes, while potentially collecting less income-tax revenue from billionaires in future years.
For California families who may never come close to paying the tax themselves, that broader economic question could prove more important than the tax rate.
Will Proposition 40 primarily deliver new money for public services?
Or will it change the financial decisions of some of California’s wealthiest taxpayers?
Voters will decide on November 3.
Whatever the outcome, the fight over Proposition 40 shows that California’s larger debate over taxes, economic growth, government spending and affordability is unlikely to disappear anytime soon.
