Alexandra Roulet Discussion of: Closing Schools?
基于德国2020年夏秋季数据，利用各州学校假期外生变化，发现学校在SARS-CoV-2传播中作用有限，并解释了先前研究中开学后感染下降的异常发现。
This paper shows that in Germany, schools played a limited role in the transmission of SARS-CoV-2 over the summer and fall of 2020. This finding is consistent with contemporaneous work by Isphording et al. (2021) which also looks at the effect of school closures on the spread of SARS-CoV-2 in Germany in 2020. The paper being discussed here shows an increase in cases just before school re-openings at the end of the summer, probably due to returns from travels. It also highlights that the puzzling finding in Isphording et al. (2021) of a fall in infections after schools re-opened was driven by two states which experienced differential pre-trends. The paper has many strengths. First, it relies on a very nice research design. School holidays in Germany vary across states following a calendar decided years in advance and thus provide variations in school closures/openings that are credibly exogenous to the spread...