Gabriel Zucman's research shows today's top 0.001% hold wealth equal to 12% of US GDP, three times worse than the original Gilded Age. His fix is a 2% minimum tax on wealth above $100 million.
Today's wealthiest Americans hold wealth equivalent to 12% of US GDP. At the peak of the original Gilded Age, with Rockefeller and the railroad monopolists, that figure was 4%. We are, in other words, three times deeper into extreme concentration than the era we use as a byword for excess. That is the finding economist Gabriel Zucman leads with, and it reframes everything that follows.
Zucman, who runs the International Tax Observatory, has spent the better part of a decade doing what he describes as detective work: tracking the hundreds of billions of dollars that flow through Bermuda and the Cayman Islands, mapping what billionaires actually pay in taxes, and building the research base for a concrete policy fix. His conclusion is blunt. Billionaires pay roughly half the effective tax rate of every other income group. The cause is simple: income tax, the tool supposedly designed to tax the rich, doesn't apply to them. When Jeff Bezos can report near-zero income in a given year and claim family benefits — legally, within the rules of the system — the system has a structural flaw, not a loophole problem.
Taxes are the dues that we pay for the privilege of membership in an organized society.
The mechanics of why billionaires pay so little are worth understanding precisely, because the fix follows directly from the diagnosis. Very wealthy people hold most of their wealth in assets: equity stakes, real estate, financial instruments. Those assets grow, but growth is not income until it is realized. A billionaire whose net worth rises by $5 billion in a year can still report a modest or negative income by offsetting gains with losses, borrowing against assets, or simply not selling. The graph from Zucman's research tells the story visually: effective tax rates rise steadily across the income distribution, then collapse at the very top.
The solution Zucman has been working on for several years is a 2% annual minimum tax expressed as a fraction of wealth, not income. If a billionaire already pays a meaningful amount relative to their wealth, nothing changes. If they have engineered their affairs to pay close to nothing, they pay the difference to reach the 2% floor. The proposal applies to those with more than $100 million in net worth. Zucman is direct about the framing: "Zero is too little. All the rest is bullshit."
A 2% wealth minimum tax closes the loophole income tax can never close — because income itself is too easy to manipulate when you're very rich.
A standard objection from wealthy individuals, when confronted with proposals like this, is that they already give generously: to museums, universities, global health causes. The Giving Pledge, launched by Bill Gates and Warren Buffett in 2010, asked signatories to commit at least 50% of their wealth to philanthropy before they died. Fifteen years later, the people who signed it became 280% richer. Only one couple fulfilled the pledge. Eight people died without doing so.
Zucman's critique of philanthropy goes deeper than scorecard problems, though. He argues the very model is a regression. The British aristocracy of the 19th century made the same argument: we're not paying taxes, but we're doing wonderful things with our money. That is not democracy. Democracy is pooling resources and collectively deciding whether they go to education, healthcare, or infrastructure. Wealthy individuals deciding for themselves where their money goes is something different, and it should not be treated as equivalent.
Philanthropy is not a substitute for paying taxes. The rich guys deciding for themselves where their money should go — that's something else.
A common response to proposals for higher taxes on the wealthy is that the economy will suffer. Zucman points to the historical record in the opposite direction. The United States in the 1950s under Eisenhower, a Republican president, had a top marginal income tax rate of 92%. Corporate tax was 50%. Estate taxes approached 70%. And growth during that period after World War II was relatively high. Investment rates exceeded today's. Innovation was substantial. The one thing notably different from today was that income and wealth inequality was dramatically lower.
The counterargument from the right, Zucman notes, is that nobody actually paid 92% — they hired accountants and lawyers to get around it. His answer: that was partly the point. A 92% rate made it essentially worthless to engineer super-high incomes. The effect was a functional ceiling on how much any individual could accumulate annually, regardless of whether anyone ever wrote a check for the full amount.
"You're a selfish, unpatriotic idiot if you don't pay your taxes." — Franklin D. Roosevelt
The most persistent objection to wealth taxes is mobility: if you raise taxes on the rich, they move to Dubai. Zucman's response is that this is a policy choice, not a law of nature. The United States already uses citizenship-based taxation, meaning Americans owe US taxes regardless of where they live. Other countries immediately stop taxing residents the moment they leave — but they don't have to.
California's proposed one-time 5% billionaire tax is a case study in how this argument gets deployed. The tax was written to apply to anyone who was a California resident as of January 1, 2026. Moving after the fact changes nothing. And yet coverage was dominated by warnings about billionaires fleeing, despite the fact that flight was legally irrelevant. Zucman attributes much of this to the structure of media ownership: a lot of private media is owned by billionaires, which is a real and unsolved problem for public discourse on these questions.
The broader point is that tax avoidance at this scale is not some force of nature. It was built, deliberately, by very rich and very powerful people, mostly starting in the 1970s and 1980s when trickle-down ideology made tax avoidance not just tolerated but encouraged. Swiss bank secrecy, which seemed permanent for decades, ended when the US threatened sanctions against Swiss banks and more than 100 countries agreed to automatically exchange banking information. Things that look immovable can move.
Brazil's G20 presidency in 2024 put billionaire taxation on the agenda of global finance ministers for the first time. These ministers had been meeting for years discussing the world's most pressing problems, and inequality and taxation had never made the list. Brazil changed that. The French National Assembly passed legislation in February 2025 embodying a minimum billionaire tax; it is currently blocked by the Senate but has already been through a democratic vote. Public support in polling across country after country runs above 80%. In France, 86% of the population supports what has become known informally as the Zucman tax.
Zucman draws a historical parallel to the creation of income tax itself. At the end of the 19th century, progressive income taxation was a fringe international movement. For centuries, all taxation had been based on consumption taxes: salt, goods, indirect levies that fell on ordinary people. The idea of taxing income progressively, with higher rates for higher earners, was greeted by the wealthy with exactly the same catastrophist arguments used today. They predicted competitive collapse, economic ruin, a flight of entrepreneurship. Democracy eventually prevailed over those arguments, and it did so because small groups of committed people refused to stop pushing.
"If you can achieve all your goals during your lifetime, you're probably not thinking big enough." — said to Zucman recently
The work now, as Zucman sees it, is building the talent base on the reform side. Billionaires have armies of accountants and lawyers. The research exists, the ideas exist, the public support exists. What's needed is more people who can craft the actual tax laws, build coalitions, and carry the argument into policy rooms where it hasn't yet reached. That recruitment is active. The School for Moral Ambition is launching a global tax fairness fellowship, looking for campaigners, lobbyists, and coalition builders across North America, Europe, and Africa.
The defining contest of the 21st century, in Zucman's framing, is between democracy and oligarchy. Tax policy has historically been the most effective tool democracy has had in that contest. That fight is underway right now, and by his account, it is beginning to move.
