In an effort to reduce viral transmission, many schools are planning to reduce class size if they have not reduced it already. Yet the effect of class size on transmission is unknown. To determine whether smaller classes reduce school absence, especially when community disease prevalence is high, we merge data from the Project STAR randomized…

Due to the COVID-19 pandemic, schools across North America closed to in person learning in March 2020. Since then, it has becoming increasingly clear that physical distancing will need to be prolonged in the 2020/2021 school year and possibly resumed in the future. In response, education ministries shifted teaching and learning online. Research is…