See healthcare journalist David Ewing Duncan writing on May 8 about a preprint article - Kai et al. - arguing that 80% mask wearing rate is practically as good as 80% herd immunity for cutting infection rates with COVID-19.
In the graphic below, from Kai et al., red and yellow are different but high rates of masking; blue is "lockdown continues indefinitely." Gray is conventional success of social distancing w/o masking.
I can't speak to the quality of the input data or the model in Kai et al. I did notice, they substantially raise the stakes in terms of the sophisticated formatting of a pre print article. See below.
|Kai et al: Much more elaborate preprint formatting (click to enlarge)|