We don't have the infection rate pinned down, but signs suggest the R0 range is higher than flu. We also have some confidence that the hospitalization rate is greater. We aren't flying blind in terms of genomic epidemiology, which does provide clues of the infection rate and the physical spread. https://nextstrain.org/ncov?c=country No doubt, doctors shouldn't decide when the economy is reopened. But I don't expect Trump to make a data-driven call. My guess is the sweet spot is somewhere between 15 days and one year. Just giving enough time so that everyone has a supply of surgical masks could get us closer to striking a rational balance. In China, you need to wear a mask if you are out in public, not so much to protect yourself, but to reduce your chance of infecting others. We know that works. If everyone in the US returned to work with ample supply of surgical masks, that could increase economic activity while minimizing the burden on hospital systems.