New COVID Cases in States Where Masks Are Required Versus States Where Masks Aren’t Required

My Grove City College colleague Gary Welton wanted to know more about the association of mask requirements with number of new cases of COVID-19. One way to examine this is to look at states where masks are required compared to states where they aren’t. In this scenario, the actual mask wearing can’t be controlled. However, this analysis examines the policy and the association with number of cases per 100,000 in population. Here are Gary’s findings when he examined new cases in the 35 states where mask mandates are in place compared to states where maskes are not required for the week from 9/2 to 9/8/20.

About the findings, Gary said, “In fact, for the recent week, states that have mandated masks show about half the number of infections per 100,000 people. Given the current data, it is prudent to wear a mask.”

I realize that even in states where masks are required, not everybody wears them. However, if I am a policy maker, I would have to look at this at least twice and wonder what is going on. Ideally, Gary will continue this analysis as the pandemic continues to see if the relationship continues. For now, this adds one more point of support for wearing masks as a means of reducing, though not eliminating, the spread.


3 thoughts on “New COVID Cases in States Where Masks Are Required Versus States Where Masks Aren’t Required”

  1. California right now has an Rt (rate of transmission) around .8, i.e. five current infections will only infect four others. If we can stay that way, we should see cases dropping in-state.

    However, school reopenings are on the horizon, with the accompanying superspread events.

    Oh, and the Sturgis Motorcycle Rally?


    There’s now upswings in cases in several Midwest states that are tracing back to them.

  2. Very interesting, and thanks for sharing, Drs. Welton and Throckmorton.
    However, it would be interesting to study a time period removed from schools and universities reopening, as I’m sure the data for the first week in September is chaotic.

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