The academics who paid this wealth tax chose their moment well. Within days of taking office, Andy Burnham stood outside Downing Street, vowing to clarify how he would pay for the policies he intended to implement. By Tuesday afternoon, he was scheduled to present his whole tax and spending plans. Into that gap stepped Gabriel Zucman and Ben Tippet with a proposal that would touch fewer than a thousand households and raise £10bn a year. For a government about to make its first real choices on revenue, the timing was not accidental.

Burnham has spent years road-testing versions of this argument. In 2021 he called for a range of wealth taxes to fund a National Care Service. Long before that, as an MP promoting what became known as the dementia tax debate, he proposed a levy on estates to fund social care, describing it as an attempt to extend the founding principle of the NHS into the care system. The instinct behind Tuesday's proposal, that the very wealthy should be asked to underwrite services the rest of the population depends on, is not new to him. What is new is the position he now occupies to act on it.

His advisers have so far preferred the quieter route, lifting the capital gains tax threshold towards parity with income tax rather than building an entirely new mechanism for taxing accumulated wealth. That preference is understandable. A minimum wealth charge would require HMRC to value property, private businesses, art and pension wealth for a small number of families, and to hold them within the tax for a decade after they leave the country. It is administratively heavier than adjusting an existing rate. But it is also more visible, and visibility is precisely what makes it useful to a prime minister who has said he wants to be seen doing something rather than merely adjusting numbers that few people notice.

The NHS gives that choice weight beyond rhetoric. The waiting list stood at 7.3 million in May, average waits across specialties running past twelve weeks. The maintenance backlog across NHS buildings and equipment has reached £15.9bn, prompting even the government's own ten-year capital plan to face questions from the King's Fund about whether the sums committed match the ambitions set out. Staff vacancies remain in the hundreds of thousands. Against numbers like these, £10bn a year is not an abstraction. It is close to the scale of investment repeatedly cited as necessary to make a dent in the capital backlog alone, before any of it reaches workforce pay or elective recovery.

The distinction between Burnham's two options is not simply rhetorical either. A capital gains adjustment raises money quietly, spread across a wider set of taxpayers, and fits within a Treasury orthodoxy that treats revenue-raising as a technical exercise best kept away from public argument. A wealth tax on a defined, tiny cohort does something different. It tells the public exactly who is paying and why, and it invites scrutiny of what the money buys in return. For an NHS that has spent years absorbing funding announcements that arrive without a clear account of what they will fix, that clarity has its own value, whatever the practical difficulties of collection.

None of this guarantees the wealth tax survives contact with the government. Zucman's own research on avoidance among ultra-wealthy households, and the report's insistence that most historical wealth taxes failed because of low thresholds and broad exemptions rather than the concept itself, will be tested against a Treasury that has just inherited an economy already straining under existing commitments. But the argument Burnham now has to make is no longer whether fairness matters. It is whether he is willing to attach a number people can see to a principle he has held for fifteen years, at the exact moment the NHS needs him to.