If we declare victory before we achieve it, we could have the worst of both worlds — a burst in new infections leading to a second shutdown, a collapse of faith in the authorities, more deaths, and a deeper depression. Letting up on an epidemic before it has run its course can create a second wave, as in 1918, and as feared in China right now, that would take the country down in the fall of an election year. At the same time, if quarantine and social distancing are stretched out too long, we could be losing more lives in the aggregate than we would be saving. We could also be risking ever-more extremist politics or even civil disorder. Gun sales are, somewhat ominously, through the roof.

What matters is the timing. Getting that right is the single biggest challenge as we go forward. But that requires a huge amount of data we don’t yet have: specifically, a much better sense of just how widespread COVID-19 is in the broader population. And we need equipment we don’t yet have: tests for the virus that are quick and easy and ubiquitous; and, perhaps more importantly, serological tests, to see who is now immune and can return to work and normal life. The British and the German governments are duly thinking of issuing immunity certificates to those who’ve recovered from the virus. If there is anyone faintly competent in the Trump administration, maybe they should think about it too. (My only worry about this idea is that it might encourage some people to go out and proactively get the virus, risking their health, just so they can get back to work.)