Global leaders had some difficult talks at the recent G20 summit in Buenos Aires. But there was clear consensus on at least one topic: the need to prepare for the risks to economic growth, whether from tightening financial conditions or trade and political tensions, which are clearly gathering.

Ten years ago, central banks played a huge role in lifting countries out of what could have been a recession as severe as the one in the 1930s. A co-ordinated fiscal stimulus was orchestrated and took place for a couple of years, but then was halted in some countries, not least in Europe, where the sovereign debt crisis hit the eurozone some years after the global financial crisis.