[robhunter]

The most convincing data I've seen is from Spain (https://www.tabletmag.com/sections/science/articles/cult-mas...)

They masked 6+ year olds and did not mask anyone under 6 in school.

You'd expect higher rates of Covid in the 5 year olds than the 6 year olds.

In fact, it was the exact opposite - rate of spread was perfectly correlated with age. Masks showed no impact.

There's also interesting data from North Dakota (https://twitter.com/TracyBethHoeg/status/1470072066380419072).

This is a great dataset because it controls for a lot of variables - it's two school districts in the same county; one optional and one mandatory. The mandatory masking county consistently has had higher rates of Covid.