Masks reduce the spread of Covid-19. But just how much of an effect do they have? A study co-authored by an MIT professor finds that if the U.S. had introduced a uniform national mask mandate for employees of public-facing businesses on April 1, the number of deaths in the U.S. would likely have been 40 percent lower on June 1.
“It is a very effective policy that includes relatively little economic disruption,” says Victor Chernozhukov, a professor in the Department of Economics and the Statistics and Data Science Center at MIT, and one of the authors of a paper detailing the study’s results. “We found it produced a considerable reduction in fatalities.”