Gabriel Zucman has spent years arguing that the world’s richest people are not simply very wealthy, but unusually good at arranging their affairs so that normal tax systems barely touch them.
That argument is now moving from economics seminars into mainstream politics. Zucman, a French economist at the Paris School of Economics, is one of the key figures behind the push for a global minimum tax on billionaires. His proposal is simple enough to explain, which is probably why it has travelled so quickly: anyone with more than £100m in wealth should pay at least 2% of that wealth in tax each year, unless they already pay an equivalent amount through income tax.
The idea brought him to The Rest Is Politics: Leading, where he sat down in Paris with Rory Stewart and Alastair Campbell for a conversation about inequality, tax havens and whether the current shape of capitalism can survive the widening gap between the very rich and everyone else.
The interview has generated a striking reaction online, with many viewers less focused on Zucman’s calm explanation of the policy than on Stewart’s visible discomfort with it.
Why Zucman thinks this matters
Zucman said his own thinking was shaped by the years he spent at Berkeley, in California, where extreme wealth and extreme poverty sit almost on top of each other. “In the Bay Area of San Francisco, you have extreme wealth. You have the world’s top billionaires and you have extreme poverty, tens of thousands of homeless people.”
He said that year after year, the situation appeared to be getting worse, while mainstream politics, particularly the Democratic Party in the United States, failed to offer a serious answer.
For Zucman, this is not just a Californian problem. He described the explosion of billionaire wealth as one of the defining features of the global economy over the past 15 years.
That is the backdrop to his proposed minimum tax. His argument is not that billionaires should be punished for being rich, but that tax systems should stop allowing the very richest to pay lower effective rates than people earning ordinary salaries.
The 2% proposal
Zucman’s central proposal is a 2% annual minimum tax on wealth above £100m.
The important word is “minimum”. Zucman is not saying every billionaire should pay a new tax on top of everything else regardless of what they already contribute. His argument is that if someone with more than £100m in wealth already pays enough in income tax to reach that minimum level, they pay no extra. If they do not, they make up the difference.
He said the 2% figure is not plucked from the air. If the very wealthy earn an average return of around 6% a year on their assets, a 2% wealth tax would be roughly comparable to a 33% tax on that return. His point was that many upper-middle income earners already pay rates around that level, while the richest can often structure their income so that the tax system barely sees it.
Zucman also explained why the threshold is set so high. The problem he is targeting, he said, becomes especially visible above £100m, where income tax starts to disappear as the super-rich hold wealth through companies and other structures rather than taking conventional taxable income.
On the UK, he cited a sharp change in wealth concentration. In 1989, he said, the 200 wealthiest families in Britain owned wealth equivalent to 5% of GDP. Today, that figure is closer to 20%.
Stewart’s challenge
Stewart pressed Zucman repeatedly on the usual objections to a wealth tax.
Would it discourage entrepreneurship? Would billionaires leave? Would it raise enough money? Was it really a practical policy, or just a politically attractive slogan?
Zucman’s answers were measured. He said that in a decade teaching at Berkeley, where many of his students went on to start companies, he had never met anyone who said they would be put off entrepreneurship by the remote possibility that they might one day become a billionaire and pay a 2% wealth tax.
On mobility, he rejected the idea that tax competition is inevitable. Countries choose how their tax systems work. The United States already taxes citizens even when they live abroad, and Zucman argued the UK could adopt a “trailing tax” for people who leave after building up large fortunes here. He noted a similar principle already exists in parts of the UK tax system, including inheritance tax.
The exchange became more pointed when Stewart and Campbell moved from the mechanics of the policy to the principle behind it.
Campbell asked the question that has since framed much of the reaction: would Zucman still want a billionaire tax if it raised no revenue?
That is a revealing question because it gets to the split at the heart of this debate. Some people see a wealth tax mainly as a way to fund public services. Others see it as a matter of fairness, democratic stability and equality before the law.
Zucman’s case straddles both. He argues that the tax would raise money, but also that a society cannot function properly when the wealthiest people are able to opt out of the tax rates that apply to everyone else.
How much money could it raise?
For the UK, Zucman put the potential revenue at around 0.5% of GDP, roughly £15bn a year.
He was careful not to oversell it. That would not solve Britain’s entire fiscal problem. It would not remove the need for difficult spending choices. It would not turn a struggling state into a wealthy one overnight.
But he drew a pointed comparison with recent rows over much smaller sums. He said Kwasi Kwarteng had tried to raise around £1.5bn by removing fuel allowances from pensioners, while his own proposal could raise around 10 times that amount from roughly a thousand very wealthy families who, in his view, currently pay very little tax relative to their wealth.
That contrast is why the argument has political force. Zucman is not presenting the tax as a magic money tree. He is asking why the burden of fiscal discipline so often falls on those with far less room to absorb it.
The history lesson
One of the strongest parts of Zucman’s argument concerned tax history in the United States.
He noted that from the 1930s to the late 1970s, America had far higher top marginal income tax rates than it does today. The top rate averaged around 78% across that period and exceeded 90% during and after the Second World War.
Zucman’s point was not that Britain or America should simply copy that model now. It was that very high top tax rates did not prevent the US economy from growing. In fact, he argued growth was stronger in that period than it has been since 1980.
His wider claim is that high tax rates at the very top change incentives. They make it less attractive for executives, financiers and company owners to extract extraordinary pre-tax incomes. In his view, much of that income is not the reward for creating new value, but the result of bargaining power and rent extraction.
That is one of the reasons Zucman’s critics find the argument uncomfortable. It does not just ask whether the rich should pay more. It asks whether some fortunes are built through systems that allow the richest to take too much in the first place.
Why the reaction focused on Stewart
The interview has produced a loud online response, much of it aimed at Stewart.
Some viewers felt he was doing what an interviewer should do: testing a policy that would be difficult to implement and politically explosive. Others saw something different, arguing that he seemed more troubled by the idea of taxing billionaires than by the scale of wealth concentration itself.
One viewer, Marteenez_, summed up the pattern many critics heard: “Rory to Gary [Stevenson], you’re not an economist. Rory to Gabriel, you’re an economist, but you’re not an expert on UK law or the budgetary process. I think we can all see where this is going.”
ReeceBland pointed to Zucman’s credentials, writing: “Just so everyone knows before watching, Zucman’s 2% proposal was endorsed by 7 Nobel Prize winning economists.”
Others focused on the mood in the room. arkiheht wrote: “Never in my life have I seen two people tap dance and struggle to control their abject fright at the ideas being suggested to them.”
FrugalDexter put it more bluntly: “Zucman absolutely bitch slapped Rory throughout this interview. You could tell he wanted to jump in so many times, but he couldn’t come up with anything.”
That was not the only view. Some listeners defended Stewart’s approach, saying a policy of this scale should face hard questions before being treated as workable. Others argued that asking whether Zucman would still support the tax if it raised no revenue was a fair way to separate the fiscal argument from the moral one.
The reason the clip travelled is that it exposed exactly where the argument now sits. Wealth taxes are no longer a fringe idea that can be dismissed without engagement. But the political class is still visibly unsure how to handle them.
Why the UK debate is moving
Zucman’s appearance comes as Britain is already arguing more openly about wealth taxation. Gary Stevenson has repeatedly argued that the UK faces a choice between taxing wealth or continuing to squeeze public services and the welfare state, and told Newsnight that Britain has “got a trillionaire class now” growing wealth at 20% a year. He has name-checked Zucman’s work directly as evidence that the case for taxing extreme wealth is not fringe activism, but part of a serious body of economic research.
Other economists and writers have made related arguments about wealth concentration, political instability and the long-term dangers of allowing a small class of people to accumulate vast economic power. Jayati Ghosh has separately made the case for moving beyond GDP as the measure of economic success, while Clara Mattei has argued the current concentration of wealth mirrors historical patterns that preceded serious political instability, including the conditions that produced fascism after the First World War.
That does not mean Zucman’s proposal is guaranteed to work. There are unresolved questions about valuation, avoidance, international coordination and how aggressively governments would need to police exits. Those are real questions.
But the political terrain has shifted. Ten years ago, a billionaire wealth tax could be dismissed as unrealistic before the conversation began. Now, the richest families in Britain hold such a large share of national wealth that the burden of proof is starting to move.
The question is no longer only whether a wealth tax is practical. It is also whether the current system is defensible.
France, the far right and the politics of taxing billionaires
Zucman also spoke about France, where he said public support for his proposed 2% minimum tax is extremely high, at around 86%. He argued that the far right’s opposition to the policy could become a political weakness. Marine Le Pen and Jordan Bardella have rejected the idea, saying billionaires would simply leave. Zucman said that position amounts to treating billionaires as untouchable, which he believes cuts against the principle of equality before the law.
That argument is likely to become more important as wealth taxation moves from academic debate into election campaigns. Populist parties often rail against elites, but many are far more comfortable attacking migrants, welfare claimants or public institutions than confronting billionaire wealth directly.
Zucman’s proposal forces that contradiction into the open.
Where the interview leaves the argument
The most striking thing about the conversation was not that Stewart challenged Zucman. He should have done. Wealth taxes are complicated, and any serious proposal deserves scrutiny.
What made the interview stand out was the gap between Zucman’s calm certainty and the visible discomfort his argument seemed to create.
He was not offering revolution. He was not calling for the abolition of capitalism. He was making a technical case that people with extreme wealth should face a minimum tax rate broadly comparable to the rates already paid by many people who are much less rich.
For some viewers, that made the pushback look oddly disproportionate.
For others, it showed why the policy needs proper testing before politicians adopt it.
Either way, the interview landed because it captured a debate that is no longer going away. Britain is short of money, public services are under strain, and wealth at the very top has grown dramatically. The old answer was that taxing billionaires sounds nice but cannot be done.
Zucman’s answer is that it can be done if governments choose to do it.
And judging by the reaction to this interview, that is exactly the part some people still find hardest to hear.
You can watch it below:
One response to “Gabriel Zucman calmly explained a billionaire tax and Rory Stewart looked deeply uncomfortable”
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Great education thank you, I don’t believe it was ideological language, I think he presented a practical solution to inequality and social mobility!
For me it’s more about the macro question of legislating to ensure wealth is distributed better for the economy that suits the many rather than the minority!
It’s about directing fiscal policy for the greater good, at the moment the narrative and rhetoric is where Rory’s instincts showed up!
Why are we all brainwashed that you can’t go anything!
We should focus on eradicating privilege and nepotism that is killing society because it leads to the wrong people ending up in the wrong places, as you know Rory because yoh had to suffer Boris!
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