There are problems with wealth taxes but avoidance, for once, isn't one of them

Taxing illiquid assets is, well, taxing.

Fraser Nelson, editor of the Spectator, has a column in today's Telegraph arguing that George Osborne needs to learn the lesson that "wealth taxes simply don't work". He writes:

The problems involved were fairly basic. Do you tax people’s worldwide wealth? If so, those much-needed businessmen will stay away. Do you tax only British wealth? Then people will move their investments abroad. The Treasury warned Healey that the proposed wealth tax was “political dynamite” – and not in a good way. At a time when Britain was in a desperate economic state, it risked dragging the country down further still. Healey gave up, saying he could not find any wealth tax that would be worth the political hassle.

This is disappointing, because Nelson is largely duelling with straw men here. It is indeed true that a tax on overall wealth could well lead to tax avoidance by the relatively simple tax planning strategy known as "keeping your cash in a Swiss bank account". The thing is, that isn't actually that much of a problem. After all, people avoid income tax as well, yet somehow we struggle on.

The measure for a tax is never "will everyone pay it rather than put their energy into avoiding it?", but "will enough people pay it to make it worth our while?" That's a different calculus, and one which Nelson doesn't address.

But the real disappointment is that, for all Nelson talks about the rising support for a wealth tax, he neglects to mention that most of that support is for taxing a very specific type of wealth: property. It's a shame, because that sort of tax – a "mansion tax", a "land value tax", or whatever form it takes – has its own set of problems which are under-discussed.

The important thing to note about property taxes do is that they completely fix the problems Nelson is concerned about when it comes to wealth taxes in general. You can keep money overseas, but a house in Britain is rather stuck where it is. To the extent that such a tax it increases the cost of living in Britain, it may keep wealthy foreigners away – but only those who haven't already been put off by the extraordinary cost of the sort of houses wealthy foreigners buy.

The thing is, land and property taxes aren't the golden bullet that many on the left like to think, for the key reason that houses aren't particularly liquid assets.

We've all heard the sob-story of the elderly pensioner who could be forced to sell the house he's lived in all his life to pay the land value tax (although we rarely hear it alongside its counterpart, the elderly pensioners who are being forced to moved out of houses they've lived in all their lives because of benefit cuts), but the key concern with such a tax is related to that problem.

If you are taxed, say, 20 per cent of your cash holdings, you pay that tax by handing 20 per cent of your cash to HMRC. If you are taxed on 20 per cent of the value of your land, you can't just hand a wing of your house over to the taxman. You either have to have the cash equivalent available, or sell your house.

Taken individually, that's not the end of the world – few will cry too hard if the odd landowner has to sell a few acres to pay the bill. The problem comes if the tax is set high enough that that sort of sale becomes commonplace.

If too many people end up trying to sell their mansions or land at the same time, then you're stuck with a sadly inevitable collapse in the price that land can go for. That's not just unfair – it means you would be taxing people on assets which are no longer worth what they were when you assessed them – it's also staggeringly inefficient. A well-designed tax should not encourage a fire-sale of assets.

These problems aren't insurmountable, by any means. But they do give pause for thought when considering the truely radical proposals like Peter Tatchell's plan to set the wealth tax rate at 20 per cent. Although back-of-the-envelope calculations suggest such a tax would generate truly staggering revenue, a more modest rate would be a better idea – at least at the start.

This mansion, in Kensington, London, was once the most expensive in the world. What'd the tax be? Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Ukip's Nigel Farage and Paul Nuttall. Photo: Getty
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Is the general election 2017 the end of Ukip?

Ukip led the way to Brexit, but now the party is on less than 10 per cent in the polls. 

Ukip could be finished. Ukip has only ever had two MPs, but it held an outside influence on politics: without it, we’d probably never have had the EU referendum. But Brexit has turned Ukip into a single-issue party without an issue. Ukip’s sole remaining MP, Douglas Carswell, left the party in March 2017, and told Sky News’ Adam Boulton that there was “no point” to the party anymore. 

Not everyone in Ukip has given up, though: Nigel Farage told Peston on Sunday that Ukip “will survive”, and current leader Paul Nuttall will be contesting a seat this year. But Ukip is standing in fewer constituencies than last time thanks to a shortage of both money and people. Who benefits if Ukip is finished? It’s likely to be the Tories. 

Is Ukip finished? 

What are Ukip's poll ratings?

Ukip’s poll ratings peaked in June 2016 at 16 per cent. Since the leave campaign’s success, that has steadily declined so that Ukip is going into the 2017 general election on 4 per cent, according to the latest polls. If the polls can be trusted, that’s a serious collapse.

Can Ukip get anymore MPs?

In the 2015 general election Ukip contested nearly every seat and got 13 per cent of the vote, making it the third biggest party (although is only returned one MP). Now Ukip is reportedly struggling to find candidates and could stand in as few as 100 seats. Ukip leader Paul Nuttall will stand in Boston and Skegness, but both ex-leader Nigel Farage and donor Arron Banks have ruled themselves out of running this time.

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Ukip’s membership declined from 45,994 at the 2015 general election to 39,000 in 2016. That’s a worrying sign for any political party, which relies on grassroots memberships to put in the campaigning legwork.

What does Ukip's decline mean for Labour and the Conservatives? 

The rise of Ukip took votes from both the Conservatives and Labour, with a nationalist message that appealed to disaffected voters from both right and left. But the decline of Ukip only seems to be helping the Conservatives. Stephen Bush has written about how in Wales voting Ukip seems to have been a gateway drug for traditional Labour voters who are now backing the mainstream right; so the voters Ukip took from the Conservatives are reverting to the Conservatives, and the ones they took from Labour are transferring to the Conservatives too.

Ukip might be finished as an electoral force, but its influence on the rest of British politics will be felt for many years yet. 

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