Post #1280: COVID-19 trend to 10/6/2021, Virginia K-12 school opening analysis, no change.

Posted on October 7, 2021


Currently, the U.S. as a whole is seeing 31 new COVID-19 cases / 100K / day.

Daily new COVID-19 cases for the The U.S. are now 40% lower than at the 9/1/2021 peak of the Delta wave.

That 40% decline since 9/1/2021 is made up of:

  • Three regions (South Atlantic, South Central, Pacific) where daily new cases are down by about half.
  • Three regions (Northeast, Midwest, Mountain) where daily new cases are roughly unchanged.

Data source for this and other graphs of new case counts:  Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 10/7/2021, from”  The NY Times U.S. tracking page may be found at

Final update on the Virginia school reopening analysis

Because this is a post about nothing much new happening, I thought I’d update my analysis of the impact of K-12 opening in Virginia.  Fears about school reopening seem to have faded — in Virginia, at least — so it’s a pretty good bet that a) once again, I’ll see nothing and b) there’s no practical point to continuing this.

Recall that I’m using the staggered opening dates of K-12 schools across Virginia as a “natural experiment”.  If school reopening generates a lot of new cases, we ought to see the share of new cases attributable to the school-aged population rise.

But that’s not happening.  Maybe there’s a little upward drift.  Maybe not.  But it bears no relationship to when K-12 schools opened.

Source:  Analysis of data from Virginia Department of Health, and school calendars from Virginia Department of Education.  This embodies a crosswalk of school district to Virginia health district.