Has outgoing European Central Bank president Mario Draghi made life easier or harder for his successor Christine Lagarde, by all but promising easier monetary policy, notably lower interest rates?

On the one hand, a newcomer’s task is simplified by an established policy line — especially if that line is sensible which, in light of economic weakness and persistently low inflation, it arguably is. (Markets do not expect the ECB to get anywhere near its 2 per cent inflation target, not even in the long term.)

On the other hand, there is a problem: with the ECB deposit rate already minus 0.4 per cent, the scope for meaningful cuts in interest rates seems limited. This credibility problem with interest rate policy requires the ECB to overcome two obstacles.