Remember the lesson of Shaun of the Dead: some zombies eventually come back to life

Funny how little phrases go viral. Suddenly everyone’s talking about ‘fasting diets’, ‘zombie companies’ and ‘leadership plots’. As to the first, the idea of the ‘5:2 intermittent fasting diet’, I gather, is to eat as little as you can for two days a week. It’s all over the media, and any moment now someone will call George Osborne’s fiscal strategy ‘the 0:7 fasting diet that’s starving us of protein for growth’, or some such. There you are, Mr Balls: yours on a plate, as it were.

But ‘zombie companies’ are not so easy to explain. Financially speaking, these are businesses that are surviving but unable to invest in new capacity, kept alive only by low interest rates and banks’ unwillingness to convert them into bad debts by pulling the plug. More loosely, the phrase applies to retailers — the likes of the Blockbuster video chain, which went under last month — that go on trading long after their high-street business models are overwhelmed by online alternatives.