Social distancing didn’t meaningfully reduce the number of deaths from the Spanish flu a century ago because it didn’t last long enough, says a new research paper that has implications for the response to Covid-19. Harvard University economist Robert Barro writes that “the likely reason” school closings, prohibitions on public gatherings, and quarantines and isolation in various U.S. cities didn’t save many lives is that they “had an average duration of only one month.” “The lesson for the ongoing coronavirus pandemic in 2020 is that, to curtail overall deaths, the NPIs [non-pharmaceutical interventions] used have to be maintained for substantially longer than a few weeks. Most likely, 12 weeks work much better than 4-6 weeks,” Barro writes in the National Bureau of Economic Research working paper. Barro's calculation doesn't take into account the economic losses from an extended shutdown. But in an email, he says any decline in gross domestic product has to be weighed against the economic value of saving lives. He uses $10 million for the value of a single life, based on estimates of how much additional money people demand to be paid for jobs that increase the risk of dying. At 12 weeks, he says, the benefits from a shutdown exceed the costs. Source
