And yet, with all this extra borrowing and all this spending Britain's economy is still tanking. Perhaps this suggests that massive deficit spending isn't the answer. That's one interpretation. Not for Krugman. To him the problem is that even the record levels of borrowing which will see Britain's national debt increase by 60 per cent, from £1 trillion to £1.6 trillion, by the next election, are not enough. We need to borrow more. That, he claims, would solve our debt crisis.  

Krugman's new book (its recommended retail price an aggregate demand boosting £14.99) is called End This Depression Now! (Norton) as though that hadn't previously occurred to anyone else. Indeed, it's possible that if George Osborne decided to increase borrowing to 10 or 12 per cent of GDP we might have a quarter or two of growth. Labour managed to boost GDP growth to 1 per cent by dumping £160 billion of borrowed money into the economy. 

But after that? Don't ask Krugman. He follows John Maynard Keynes who, accurately but none too helpfully, observed: "In the long run we are all dead." Actually, if you did ask Krugman, you might get a response like the one he gave when the dot com bubble burst: "To fight this recession the Fed needs . . . soaring household spending to offset moribund business investment . . . Alan Greenspan needs to create a housing bubble to replace the Nasdaq bubble."

That worked out fine, didn't it? Well yes, in Krugman's terms it did. Sure, we are now living with the effects of the bursting of that bubble but we did get a few good years of rocketing property prices which made us all feel as though we were getting richer just by sitting in our homes. And now that bubble has burst we just inflate a new one somewhere else. And when that bursts we inflate a new one. And when that bursts . . .