Given their reputation for ducking decisions and for deferring to bureaucrats, it is not every day Japanese leaders are praised for potent policymaking – but these are extraordinary times.

Even as Japan on Wednesday published a record 4 per cent quarter-on-quarter fall in first quarter gross domestic product, the International Monetary Fund was praising the masters of the world’s second-largest economy for their handling of what is unquestionably its worst postwar slump.