It is difficult to do empirical studies of the effectiveness of maskrequirements, partly because there is no objective way to determinehow often any person wears a mask (or which kind, properly or not,etc.) A group of scientists did a meta-study and found some evidencein favor of concludingmasks reduced Covid,but not enough for realconfidence.Then one of them, who had antimask leanings, made the bizarre claimthat the evidence supports the opposite conclusion. But that seems tobe misleading words.