“I don’t think corona is as big a threat as people make it out to be,” the acting chairman of the Council of Economic Advisers, Tomas Philipson, told reporters during a Feb. 18 briefing, on the same day that more than a dozen American cruise ship passengers who had contracted the virus were evacuated home. Public health threats did not typically hurt the economy, Mr. Philipson said. He suggested the virus would not be nearly as bad as a normal flu season.

The 2019 study warned otherwise — specifically urging Americans not to conflate the risks of a typical flu and a pandemic. The existence of that warning undermines administration officials’ contentions in recent weeks that no one could have seen the virus damaging the economy as it has. The study was requested by the National Security Council, according to two people familiar with the matter…

Ms. Scherbina’s paper evaluates the trade-offs involved in slowing the economy to fight the spread of the virus by, as the paper puts it, “balancing its incremental benefits against the enormous costs the suppression policy imposes on the U.S. economy.”

In a best-case scenario, Ms. Scherbina concludes, a national suppression of economic activity to flatten the infection curve must last at least seven weeks. In a worst case, where the shutdown proves less effective at slowing the rate of new infections, it would be economically optimal to keep the economy shuttered for nearly eight months.