Shaky..

The CDC agency’s director has said, repeatedly, that schools without mask mandates have triple the risk of COVID outbreaks. That claim is based on very shaky science.

The Arizona study at the center of the CDC’s back-to-school blitz turns out to have been profoundly misleading. “You can’t learn anything about the effects of school mask mandates from this study,” Jonathan Ketcham, a public-health economist at Arizona State University, said. 

His view echoed the assessment of eight other experts who reviewed the research. 

But the data being touted by the CDC—which showed a dramatic more-than-tripling of risk for unmasked students—ought to be excluded from this debate.

 
 Noah Haber, an interdisciplinary scientist and a co-author of a systematic review of COVID-19 mitigation policies, called the research “so unreliable that it probably should not have been entered into the public discourse.”