4 ms·
From the study: > School districts that choose to mandate masks are likely to be systematically different from those that do not in multiple, often unobserved,
by PragmaticPulp 4y ago
From the study:
> School districts that choose to mandate masks are likely to be systematically different from those that do not in multiple, often unobserved, ways.
From my purely anecdotal observations, regions with higher rates of COVID are more likely to adopt masking requirements as a countermeasure. That correlation alone would explain why the benefits of masking become unclear when measured on a large scale.
- lern_too_spel 4y agoAnd indeed, when controlling for infection rate at week 0, mask effectiveness suddenly becomes clear in the data again. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4118566#comment-5870932122 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4118566#...
- anamax 4y agoYour link points to an argument for mask INeffectiveness. There is a comment that there's another way to look at the data that might show mask effectiveness, but the relevant analysis wasn't done.
- dragonwriter 4y agoYeah, it's kind of weird to do this kind of analysis when you have data that you include on a chart which clearly demonstrate the variable by which the groups you are concerned with are systematically different that you need to control for, and not include that among your controls, and then have a conclusion that is basically “research is hard, these groups must be systematically different in some way we haven't controlled for, but who knows what it might be”. Places that adopted mask mandates had higher baseline pediatric infection rates which were erased within six weeks.