A Look at DESE's Cited Sources: Footnote #20 and #24 - Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US

DESE Claim 1: "masks or face coverings are among the most critical components of risk reduction"

DESE Claim 2: "In the United States, states advising face masks/face coverings be worn in public saw a decline in their COVID-19 growth rates"

Cited Source: Lyu, W. and Wehby, G. L. (2020). Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US. Health Affairs. Available at https://doi.org/10.1377/hlthaff.2020.00818

Peer Reviewed?:Yes. "Editor’s Note: This Fast Track Ahead Of Print article is the accepted version of the peer-reviewed manuscript. The final edited version will appear in an upcoming issue of Health Affairs"

Study Methodology: "event study examining changes in the daily county-level COVID-19 growth rates"

Notes: Face masks have reduced the growth rate of COVID-19. "Mandating face mask use in public is associated with a decline in the daily COVID-19 growth rate by 0.9, 1.1, 1.4, 1.7, and 2.0 percentage-points in 1–5, 6–10, 11–15, 16–20, and 21+ days after signing, respectively." The study does not that it does not attempt to measure compliance with face masks orders. 

Supports DESE Claim 1?: Yes.

Supports DESE Claim 2?: Yes.