# The optimal duration of lockdown

Here is a new AEI paper by Anna Scherbina. I have not read it and am not endorsing (or criticizing) its conclusions, here goes:

We investigate the optimal duration of the COVID-19 suppression policy. We find that absent extensive suppression measures, the economic cost of the virus will total over $9 trillion, which represents 43% of annual GDP. The optimal duration of the suppression policy crucially depends on the policy’s effectiveness in reducing the rate of the virus transmission. We use three different assumptions for the suppression policy effectiveness, measured by the R0 that it can achieve (R0 indicates the number of people an infected person infects on average at the start of the outbreak). Using the assumption that the suppression policy can achieve R0 = 1, we assess that it should be kept in place between 30 and 34 weeks. If suppression can achieve a lower R0 = 0.7, the policy should be in place between 11 and 12 weeks. Finally, for the most optimistic assumption that the suppression policy can achieve an even lower R0 of 0.5, we estimate that it should last between seven and eight weeks. We further show that stopping the suppression policy before six weeks does not produce any meaningful improvements in the pandemic outcome.

I hope there is a variable in the analysis for “risk of extreme societal pressures,” though I am not sure if those are higher for extreme lockdown scenarios or for extreme “let it rip” scenarios. In any case, such risks are a significant factor in how I view these questions.

And now I must teach! (on-line, of course). But I wanted to get this up for your attention before the evening closes.