A graph that overlays data from surveys on mask usage with the number of coronavirus cases confirms studies that indicate the face coverings have no significant impact on the spread of the coronavirus. Using data culled from YouGov.com and the Covid Tracking Project from March 20, 2020, to March 3, 2021, economist Brian Westbury created the chart and posted it on Twitter. Surveys showed mask usage reached about 80% by midsummer last year and has remained consistent since then. During that period, however, the number of daily positive cases rose and fell precipitously.
