In 1930, J.M. Keynes made some startling predictions in “Economic Possibilities of Our Grandchildren” (included in Essays in Persuasion, 1931). He made those predictions at the beginning of a world economic crisis, and now, as we seem to be recovering from another world economic crisis, it is a good time to check on the seeming accuracy of his predictions. His first prediction was that the two opposed errors of the pessimism “which now make so much noise in the world, will be proved wrong in our time”—namely the pessimism of the revolutionaries and the pessimism of the reactionaries who consider…