The CDC could soon be changing its guidelines on whether the American public should be wearing masks to combat the spread of COVID-19. What does the data say about mask usage? And how do we calculate the answer for ourselves?Guest: Aaron E. Carroll, professor of pediatrics at Indiana University School of Medicine. He blogs at a website called The Incidental Economist. He’ll also answer your coronavirus questions on YouTube. His channel is Healthcare Triage.Slate Plus members get bonus segments and ad-free podcast feeds. Sign up now. Learn more about your ad choices. Visit megaphone.fm/adchoices