[jkingsbery]

The latest EconTalk episode talks about this: https://www.econtalk.org/nassim-nicholas-taleb-on-the-pandem... ... Once the Pandemic hit, we should have worn masks. Statistical studies aren't the only form of human knowledge - we understand that when we speak, air and saliva leave our mouth, carrying viruses along. Masks catch air and saliva (and as you say, have low cost). Therefore, wearing masks makes sense as a matter of logic. We don't need to drag p-values into everything.