In its latest World Economic Outlook, the IMF calls what is now happening, the “Great Lockdown”. I prefer the “Great Shutdown”: this phrase captures the reality that the global economy would be collapsing even if policymakers were not imposing lockdowns and might stay in collapse after lockdowns end. Yet, whatever we call it, this is clear: it is much the biggest crisis the world has confronted since the second world war and the biggest economic disaster since the Depression of the 1930s. The world has come into this moment with divisions among its great powers and incompetence at the highest levels of government of terrifying proportions. We will pass through this, but into what?

As recently as January, the IMF had no idea of what was about to hit, partly because Chinese officials had failed to inform one another, let alone the rest of the world. Now we are in the middle of a pandemic with vast consequences. But much remains unclear. One important uncertainty is how myopic leaders will respond to this global threat.

For what any forecast is worth, the IMF now suggests that global output per head will contract by 4.2 per cent this year, vastly more than the 1.6 per cent recorded in 2009, during the global financial crisis. Ninety per cent of all countries will experience negative growth in real gross domestic product per head this year, against 62 per cent in 2009, when China’s robust expansion helped cushion the blow.