Milton Friedman had a postulate about this. He got a Nobel Prize and all the rest of it, very fancy. But as soon as you interrogate this postulate, it’s manifestly rubbish. The postulate was that capital would move into a region hit by an adverse shock. So, Sheffield’s steel industry collapses. ‘Oh well,’ says Milton Friedman, ‘that means wages are cheaper, property is cheaper, and so capital will move in.’ Which sounds fine until you think about it for more than two minutes.