Why COVID-19 death toll predictions are improving

Throughout the COVID-19 pandemic, the nation's political leaders have leaned on grim death toll predictions to guide policies, but the numbers keep shifting, raising questions about their utility and reliability. The White House announced on March 31 that officials expect up to 100,000 to 240,000 total American deaths from COVID-19, even with social distancing policies. At around the same time, a prediction model from the University of Washington's Institute for Health Metrics Evaluation (IHME) was estimating far fewer total American deaths, totaling approximately 84,000. Now - only one week later -- the IHME figure has dropped even further, estimating 60,000 deaths by August. Still, other models have predicted different death tolls. So what happened? Why are these numbers different? These models are mathematical equations created by public health experts to help us anticipate what's next. The equations, which are processed by computers, crunch currently available data to deliver...