Strange, is it not, how politicians never ask how they could cut their own spending, but only think about how they can raise taxes from other people. Mr Balls reckons he can raise £1.2bn from the tax, which he says would come in handy for the NHS, he reckons (though the emerging black hole in the NHS budget is much larger than that). How does he know? He says much of the tax would come from foreigners with big houses in London, but does not seem to know how many of them there are. No, as usual, it will be the Great British public who foot most of the bill, and not just the rich. Tens of thousands of homes in London will be caught by it, for example, where the average price in a 'prime area' will probably hit the £2m mansion tax threshold by the time of the 2015 election. And 'prime' includes areas like Battersea and Clapham, not just swanky Kensington and Chelsea.
There are already plenty of taxes on property. Not only is there the council tax, but there is stamp duty when you buy a house and inheritance tax when you give it to your kids. Now the plan is to add another, of perhaps £4,000 a year.
We all know what will happen. The tax will be imposed on properties of £2m, and over the years, thanks to (politician-created) inflation and (politician-created) planning restrictions, the cost of property will rise. More and more properties will be hit by the 'mansion' tax (yes, including broom cupboards in Kensington), just as more and more people now pay the 40% higher rate of income tax, which was originally targeted at the wealthy but is now paid by people like teachers and police officers.
And our tax (and subsidy) system is already highly progressive. Wealthier people pay higher taxes of many kinds, while poorer areas get subsidies through the local government finance system.
The mansion tax is theft, a bit at a time. There will be many people who happen to live in large houses but have little or nothing in the way of income (such as those on pensions) with which to pay the tax. Perhaps the house was their childhood home and they can't face moving. Moving is a strain even for the most robust of us. Ed Balls says, well maybe poorer people could defer the tax until they sell the house or pass it on after their death. But that makes the tax even more complicated - it is going to need a means test and a lot of extra bureaucracy, more lines on the tax form and all the stuff that has already got us in such an overtaxed bureaucratic pickle. This is a tax we could well do without.