There has been much discussion about the effectiveness of simple masks worn by the public in slowing the transmission of Covid-19. Many agree that masks are effective in preventing the spread of the virus to others but there are several theories and measurements that try to disprove this effectiveness. I have been monitoring, among other data, the number of cases and deaths reported in Ohio. A plot of the data ending 15-Aug-2020 is available. It shows a significant decrease in New Cases Reported after the state-wide Mask Mandate was issued on 23-July. This behavior is also seen in the data for  Lucas and Wood counties, two of the 88 in Ohio. Does this not strongly support the hypothesis that wearing masks leads to a reduction in cases of Covid-19? Request the plot from ernielippert**At_Symbol_Here**toast.net.
Ernest L. Lippert, Ph.D.