If there's some trend in the world that we don't much like but has been happening for ages, there's a human tendency to assume it will keep on forever and just get worse. Occasionally, however, this moment signals it won't be long before it starts going away.

I'm a great believer in the pendulum theory of history: trends in human activity go on and on until they reach an unacceptable extreme, and then one day they turn and start going back the way they came.

That's certainly the way fashions in economics and government policy work. Consider the story since the end of World War II, using Britain as our guide.

There was a great reforming spirit after the war, and much that needed fixing. The economy wasn't working well and ordinary people – who'd done their duty so selflessly during the war – weren't getting a fair share of the economic rewards.