We don’t see this in Minnesota because if we did it would similarly show that schools requiring masks have no fewer cases than those that don’t require them, so the DOH will never release that data. The briefly did when they thought it would support their position, but now the data must not, so we won’t ever hear about it again. Kind of like that mask study. You can read this chart for yourself to see how much difference there is, i.e. none. Thanks to Twitter for the chart.
The Healthy Skeptic is a website about the health care system, and is written by Kevin Roche, who has many years of experience working in the health industry. Mr. Roche is available to assist health care companies through consulting arrangements through Roche Consulting, LLC and may be reached at 
Apple Podcasts
Google Podcasts
Spotify
Overcast
PocketCasts
Radio Public
Stitcher
Anchor
RSS - Posts
I recall the highly touted Kansas masked mandated counties v unmasked mandated county study.
Two or three significant errors in the study
1) the unmasked counties had much lower infection rates at the start of the the mask mandates , so they naturally had a large portion of the delta due to just catching up to the mean.
2) the unmasked counties had lots of anomolies in the cluster of infections. Strong indications that would seem to be unrelated to masks in public places.
3) there was a large delta at the end of the study period. 40%+ as I recall. However, I compared the infection rates for the following 3-4 weeks. Based on partial information , the 40%+ delta closed to an insignificant 10% delta.
I requested better data for the subsequent 3-4 weeks along with questions if they were going to revised the study to take into account the subsequent 3-4 weeks
However, I never received a follow up response.