Jason Abaluck just posted a report from Yale University on Twitter:
The conclusion: wear a mask when you go outside, also if you don’t have symptoms. Use a cloth mask, because it will:
– Stop 50% of the virus from going out
– Surgical masks are needed by professionals.
We have two principal recommendations: 1) everyone should immediately begin wearing cloth masks in public, 2) The govt. should immediately use all available means to increase the supply of medical masks, especially by heavily rewarding producers.
The basis for our recommendation is simple: anything that combats the spread of the virus is absurdly valuable due to the resulting reduction in mortality risk (not to mention accelerating resumption of normal economic activity).