The reason, it turns out, we can’t have this Labour proposal of a mansion tax on homes worth over £2m, is that it would cost too much to calculate.

George Osborne has said: “It’s very costly to implement. You have to send inspectors round the country valuing all homes, not just those worth over £2m.”

I suppose that’s right, though in some areas it shouldn’t take all that long. For example, inspectors sent to a council estate in Runcorn ought to get round fairly briskly, unless they’re really diligent and go: “We’d better check inside each flat, in case the kitchen is made of panda fur or the toilet’s been painted by Picasso. I had a mate inspecting a bedsit in Sunderland last week, went in the bedroom and there was the Sphinx. The kids were using it as a slide, took the value up to two million and twenty quid so you never know.”

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Maybe other institutions will adopt this attitude, and decide that money isn’t worth collecting as it takes too long to work out how much to charge. Supermarkets will announce that as it’s such a palaver going round every block of cheese and packet of Weetabix thinking of prices and mucking about with bar codes, it’s easier all round if everything was free.

Luckily, it must be far simpler to go round the house of everyone who’s on benefits, and work out if they have a room that isn’t slept in every night, and if so force them to move to somewhere smaller. This means the bedroom tax can be implemented, and that’s bound to raise far more money than the odd shilling that can be afforded by people like Roman Abramovich.

It always seems to work out that taxes on the rich are pointless, because they’ll take their money abroad or find a loophole; or the rich have antique money which you can’t collect because it’s all crumbly; or they might be footballers who will kick their money round the garden so, to get it off them, you’ll need two proven international central defenders whose wages will be more than you’ll collect.

In any case, as one columnist insisted yesterday, a mansion tax is simply “the politics of envy”. So if you feel that the cuts to libraries, services, parks and the disabled ought to be balanced by a tax on the wealthiest, who so far in these times of austerity have had their taxes cut, not only are you economically stupid, you’re committing one of the deadly sins.

It was the same when slaves complained about slavery, or medieval peasants moaned about starving in a ditch while the baron had a nightly banquet, just envy, envy, envy – and where does that get you?

That’s why the money has to come from the poor, as taking it off them can’t be envy, because no one envies them.

So we should be grateful to George Osborne. Not only is he helping the economy, he’s saving all our souls.