Every twenty years, give or take, the British Left rediscovers the wealth tax. They rediscover it with the bright-eyed conviction of a Labrador rediscovering a tennis ball under the sofa, and with roughly the same level of new information. Kristian Niemietz at the Institute of Economic Affairs has now published a paper called Fool's Gold which lays out, with the patience of a man explaining traffic to a toddler, why every wealth tax in modern history has produced less revenue than projected, more capital flight than expected, and a stack of legal challenges as tall as the parliamentary library.

I have been visiting Britain for forty years. I have watched Britain consider, propose, almost-implement, and quietly bury various wealth taxes on roughly a twelve-year cycle. The pattern is comforting in its consistency. A new Chancellor wants to look bold. A think tank with a name like the Centre for Progressive Fiscal Renewal publishes a paper. The Treasury whispers to the Chancellor that the modelling does not work. The Chancellor announces a "consultation". The consultation produces a report. The report is filed. The wealth tax dies. The cycle repeats.

Niemietz's contribution is to point out, with charts, that we already know what happens. France ran a wealth tax from 1982 until 2017. It raised, by the French government's own subsequent admission, less than the cost of administering it once you accounted for the entrepreneurs and capital that left. Norway has one. It has driven so many founders to Switzerland that the country is now, by Norwegian standards, debating whether to repeal it. Sweden had one and got rid of it in 2007 because the Social Democrats, who are not normally accused of insufficient appetite for taxation, looked at the numbers and concluded they could not look at the numbers any more.

The British case will be the same. It will be the same because the rich, contrary to a popular Labour Party fantasy, are not patriotic about their tax residence. They are patriotic about their families, their schools, their football clubs, and in some cases their dogs. They are not patriotic about HMRC. Threaten to tax their net worth annually and they will move to Lugano, Lisbon, or Dubai, and they will do so in numbers large enough to leave a hole in the revenue forecast you could drive an Ocado van through.

What Britain wants — what every advanced democracy wants — is a tax base that is broad, stable, and inert. Inert in the sense of not moving. Income from labour is inert. People do not generally relocate to Frankfurt to avoid the higher-rate threshold; they grumble and pay. Property is inert. Capital is not inert. Capital is the most mobile substance on Earth aside from gossip, and gossip at least has the decency to stay roughly where you started it.

So what to do? Niemietz, sensibly, suggests broadening consumption taxes and reforming property taxes that already exist but are bad. VAT is regressive in design and progressive in incidence; nobody wants to talk about it because nobody wants to admit that pasties are politically dangerous. Council tax is a disaster of 1991 valuations that taxes a flat in Hartlepool more heavily than a mansion in Mayfair. Fix these and you have a revenue base. Tax wealth and you have a revenue forecast.

The British Left will not read the IEA paper. The British Left does not read the IEA paper as a matter of principle. But somewhere, twelve years from now, a future Chancellor will commission a fresh consultation on wealth taxation. The Treasury will hand them a copy of Fool's Gold. They will read three pages and put it down. The cycle is, as I said, comforting in its consistency.