Shutting things down six months ago would have had no beneficial effect. Closing national borders globally in January would have had an extremely beneficial eff

Shutting things down six months ago would have had no beneficial effect. Closing national borders globally in January would have had an extremely beneficial effect, in that domestic economies could have proceeded normally while China eradicated the infection. At the current point, there's really nothing to balance. Every extra day you're open is an extra several days you'll need to remain closed, and an extra 1.2-1.4x lives lost. Closing later is strictly worse than closing now.