How might the hysteria in financial wonderland cross into the real world? So far, most central bankers are saying the credit crisis is containable and global growth will remain robust. Markets have not believed a word of it. Now, as turmoil extends into a third week, macro economists are beginning to question their forecasts.

Their initial reluctance was understandable. Global output is strong – the International Monetary Fund predicts world growth of 3.4 per cent for this year. But this rosy picture could change quickly.