If it were done when ’tis done, ’twere well it were done slowly, with no firm commitment to an end date, and with the clear promise that it will swiftly be reversed if necessary.

The European Central Bank, as predicted by most investors, yesterday announced that it would start scaling back monetary stimulus by reducing from €60bn to €30bn its purchases of assets under the quantitative easing programme it began in 2015.

However clearly it has been signalled, the move to withdraw stimulus may yet turn out to be premature. In that context, the ECB was wise also to say that the buying programme is open-ended and to confirm that, even when it is finished, the bank will wait another good while before raising interest rates. In the months ahead, Mario Draghi, the ECB’s president, must continue to underline that the bank will make up its mind on future asset purchases based on incoming economic data, not an end date planned and announced in advance.