Positivity rate is just the number of people testing positive divided by number of tests taken. It is a scam in my opinion. The local university tests everyone twice a week when in session. They have had positivity rates below 1% except for a couple weeks at the beginning of fall semester. Even then, it was at 2% for only a few days. The rest of the people in the town and county only get tested if they feel bad or it is required for work. I would take a bet that if the townies were tested as frequently as the university, there wouldn't be much difference in the positivity rates and the current mitigation rules wouldn't be justified. The state covid counters removed the university figures from our regional statistics last fall.
Zackly