> If I've reduced the odds of catching COVID19 by even, say, 30%, Given that the likelihood of catching it from a brief encounter with a random passer by is in

> If I've reduced the odds of catching COVID19 by even, say, 30%, Given that the likelihood of catching it from a brief encounter with a random passer by is in fact quite small the idea that a mask could reduce the odds meaningfully in large unconfined spaces seems unlikely. We do not wear masks here in Norway but we do keep our distance (except for usual idiots at parties, etc.). Recent clusters of infection here have all been traced to people who were in close contact with large numbers of people for hours (wedding parties, cruise ships, etc.). Then perhaps diligent use of masks might have helped but just not holding the party helps more. > For the most part, easiest thing to do is to not go out in public. This together with simple measures like making sure one washes ones hands seems to be what is working here.