Staff Reports
Six Nobel Prize–winning economists recently published an open letter urging Californians to approve Proposition 40 — the one‑time, 5% “billionaire tax.” That is the news hook. It is also a reminder: when politics gets shaky, prestige shows up to do the heavy lifting. But prestige does not change basic math or human nature.
Nobel laureates weigh in — and the campaign lights up
The letter, signed by well‑known economists including Daron Acemoglu, Abhijit Banerjee, Peter Diamond, Esther Duflo, Paul Krugman and Joseph Stiglitz, backs Prop 40 and repeats the campaign’s headline claim: a one‑time levy on Californians worth $1 billion or more would raise roughly $100 billion. The signers argue the tax is enforceable because residency is measured as of January 1, 2026, and insist it won’t “doom Silicon Valley.” Fine. That’s their political view backed by fancy résumés. It still isn’t the same thing as a proof.
Numbers don’t add up — and experts disagree
The real fight isn’t slogans or credentials. It’s the math. Proponents rely on estimates from Gabriel Zucman, Emmanuel Saez and other allies to reach the $100 billion figure. Opponents, including Hoover Institution analysts, put the central estimate far lower — roughly $35–$46 billion — after factoring in avoidance, moves out of state, and lost future income tax. California’s own Legislative Analyst’s Office gives a cautious middle answer: “tens of billions,” not a windfall. Remember, Europe tried annual wealth taxes decades ago and mostly gave up after they raised little revenue and chased investment away. Fancy letters do not erase behavioral responses or enforcement costs.
Politics, money and ballot mechanics will decide this
This has become more than an academic spat. Opponents have poured massive sums into the fight — tech billionaires and other donors are bankrolling both opposition ads and rival measures designed to wipe out Prop 40 if they get more votes. Reports show at least one major tech founder has given well over $100 million to anti‑Prop 40 efforts. Polls are razor tight. Two counter‑propositions on the same ballot, Propositions 41 and 42, could nullify Prop 40 even if it gets a majority. So the outcome looks less about Nobel opinion and more about who spends more and how voters respond to a crowded ballot box.
Bottom line: prestige won’t fix bad policy
There’s nothing wrong with economists speaking out. But a signed letter cannot make a shaky revenue model sturdier or stop wealthy people from changing behavior. Voters should treat the Nobel seal as a headline, not a guarantee. If you want to know whether a policy will work, look at enforceability, realistic revenue estimates, and past experience — not how many medals the endorsers have. In short: if six laureates told you the ocean was dry, you’d still check for water before you moved in.
