[michaelt]

> That's probably true, but how would you even find those infections?

Well, you could look at the infection rates among people who attended large outdoor gatherings during the pandemic in spite of warnings - like Trump rally attendees or BLM protesters.

Or you could look at infection rates for people who have a tractable list of possible exposures - interview only people who live alone and work from home, and see if people who only shop for food have a lower infection rate than people who shop for food and also golf once a week.

Or you could run an experiment - get some infected people, have them cough at petri dishes inside and outside, with and without masks, and at different distances.