Stanford study: California billionaire wealth tax could cost state $39 billion

A proposed "wealth tax" on California's billionaires could backfire and cost the state tens of billions of dollars in the long run.

Projected Revenue Losses

If the proposed tax drives wealthier residents out of the state, California could end up losing between $1 billion and $3.5 billion annually in income taxes, according to a working paper published this week. A pair of researchers at Stanford University warn that the state could end up losing an estimated $39 billion because of the consequences of the wealth tax.

"These findings suggest that the Billionaire Tax Act will not fulfill the primary functions for which it was designed," write researchers Benjamin Jaros and Joshua Rauh.

Proposition 40

Voters in California will decide next month whether to impose the one-time, 5 percent tax when they vote on Proposition 40). The ballot measure is dividing Democrats—Gov. Gavin Newsom opposes it, while progressive Rep. Ro Khanna (D–Calif.) claims it is the "most important ballot initiative in America and a fight for the soul of our party."

Billionaires Leaving the State

The measure is already spurring some billionaires to flee the state—including venture capitalist Peter Thiel and Google co-founder Larry Page. Including those two, the seven billionaires who have publicly said they are leaving the state represent more than $539 billion of the nearly $1.9 trillion aggregate net worth of California's billionaires, the researchers note.

With other departures likely happening more quietly, the new study estimates that the tax will generate about $30 billion, a far cry from the $100 billion that the tax's supporters expect. The "behavioral response" from billionaires in California "has eroded most of the projected tax base," write Jaros and Rauh.

Long-Term Outlook

That's still a pretty big pot of revenue. In the long run, however, the state is likely to lose out.

After running 100,000 simulations using different assumptions, the two researchers report that "85 percent of plausible outcomes produce a negative" result in state revenue.

Similar Experiments Elsewhere

Other recent experiments with special taxes on wealth have backfired in similar ways:

• In response to a new wealth tax in Washington State, Jeff Bezos relocated to Florida, and iconic Seattle brand Starbucks shifted more of its corporate headquarters to Tennessee.
• Studies have shown that a "millionaires tax" in Massachusetts contributed to wealth moving out of that state.

Capital is always mobile, despite the best efforts of politicians. And if you were a billionaire living in California, why would you stick around?

Polling

Polls show voters are narrowly divided over Proposition 40. A Politico poll published earlier this month showed 46 percent of voters plan to vote for the measure, while 43 percent oppose it. Voters were similarly divided when asked if they expected it to pass or not.