"At Cornell University in Ithaca, New York, president Martha Pollack announced that the campus would be reopening because mathematical modelling suggested that there would be fewer COVID-19 cases that way. If the campus were kept closed, many students would still live in shared housing in and around Ithaca, a survey found. These students would drive an outbreak of some 7,200 cases, according to a model created by operations researcher Peter Frazier and his colleagues. That could be mitigated if the students were on campus and being tested regularly. In that scenario, the model predicts just 1,200 cases. Others question Cornell’s rationale. Inglesby says universities should tell students from outside the area to stay at home, rather than tailoring a plan around their desire to show up. “That’s not making decisions in the right order,” he says. Cornell sociologist Kim Weeden pointed out in a tweet that the survey was carried out in late spring, when cases were declining — and it didn’t poll the parents of students. “Whoever is footing the bills may have quite different ideas on the subject,” she wrote. Frazier says that merely urging students, many of whom have already signed leases, to stay at home would be a toothless request. And although fewer students might show up than planned to do so in May, his model still suggests keeping them on campus, where testing can be required, is safest overall. “The conclusion that residential is safer than online is really, really, robust to the number of students returning,” he says."