Some time, probably soon, the punch bowl will be taken away. What happens next will be very interesting.

William McChesney Martin, long-time governor of the US Federal Reserve, pithily defined the art of central banking as “to take away the punch bowl just as the party gets going”. In other words, before the economy overheats and generates inflation, central bankers must start raising interest rates. If judged correctly, this allows the economy to adjust steadily, without booms and busts.

Unless the European Central Bank is playing some cruel practical joke, it will raise rates next week. Jean-Claude Trichet of the ECB likes to express himself through code words at his monthly press conferences. He said last month the ECB was in “strong vigilance”, which was virtually a promise of a rate rise this month.