And we have information on Covid-19 cases, at least in the first weeks of school. So far, the numbers are small. In our data, as of Sunday, confirmed case rates in students are 0.073 percent and, in staff, 0.14 percent. That means, in a school of 1,350 students you’d expect one case every two weeks and, in a staff of 100, one case about every 14 weeks. These numbers are about three times as high if we include suspected cases.
The top-line numbers are usually what people ask about first, but by starting with the context we can look at all sorts of additional information. For example: In some school districts, staff are working in person and students are not in person. Staff suspected and confirmed case rates in these schools look similar to schools that have students in person (although all are low), which suggests that staff may be spreading the coronavirus to each other, or these cases may be the result of general community spread. Another simple finding: Private schools in our data have lower infection rates, which seems to reflect, at least in part, their demographics and the fact that they do more mitigation.
Data with more context can also reveal the relative frequency of coronavirus prevention policies (masks are the most common, while routine staff testing is very uncommon) and give information on the use of different learning models. According to our data, 13 percent of schools have changed their learning model since the start of the school year. As the data grows, it will allow researchers — us and others — to analyze the relationship between prevention and outcomes. In our early analysis, limiting group sizes to under 25 seems to be the mitigation practice that is linked most strongly with low infection rates. Time and more data will help us learn whether this holds up.
As a parent, or as a school administrator, this data may give you more context for your own choices and encourage you to ask informed questions. What should I expect in a school like mine, if we open? What do “best practices” look like in general, and in my area? Information like this may be crucial to parents’ choices about their children, and schools’ choices about reopening.
Emily Oster (@ProfEmilyOster), a professor of economics at Brown University, is the author of “Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, From Birth to Preschool.”
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