New York Mayor Bill de Blasio announced this week that he was forced to close public schools—serving 1.1 million children—after the city’s coronavirus “positivity case” rate hit a seven-day rolling average of 3%. At a Wednesday afternoon news conference, Mr. de Blasio cited a “data-driven, science-driven” decision-making process. The school system, which had opened for part-time, in-person classes only six weeks ago, shut its doors the next day.
The decision angered parents, as the virus hasn’t been spreading in schools. Tens of thousands of children and staff have been tested for Covid-19, with a reported case rate of only 0.19%. The school system is thus 15 times as safe as the city at large, so it makes little sense to close the schools to fight a rising second wave of infection. Most European countries have kept schools open even while businesses remain closed. The World Health Organization advises that there have been only limited cases of student-to-student transmission, and that school closures aren’t an effective means of reducing community transmission. The Centers for Disease Control and Prevention has similarly concluded that the minor risks of keeping schools open for in-person learning are outweighed by the social and economic costs of closing them.