But business cycles as a subject for study have enjoyed a revival for at least a decade now, stimulated in part by the severity of the 1974-75 and 19… - Robert J. Gordon

The century of revolution in the United States after the Civil War was economic, not political, freeing households from an unremitting daily grind of painful manual labor, household drudgery, darkness, isolation, and early death. Only one hundred years later, daily life had changed beyond recognition. Manual outdoor jobs were replaced by work in air-conditioned environments, housework was increasingly performed by electric appliances, darkness was replaced by light, and isolation was replaced not just by travel, but also by color television images bringing the world into the living room. Most important, a newborn infant could expect to live not to age forty-five, but to age seventy-two. The economic revolution of 1870 to 1970 was unique in human history, unrepeatable because so many of its achievements could happen only once.

During the relatively brief period in the late 1960s when economists were pondering the possible obsolescence of business cycles, the scholarly discipline of macroeconomics showed signs of becoming fragmented into speciality areas devoted to components of the then popular large-scale econometric models-for example, consumption, investment, money demand, and the Phillips curve. But more recently the revival of severe real world business cycles, together with the revolutions associated with Milton Friedman's monetarism and Lucas's classical equilibrium models, has brought about a revival of interest in economic analysis that focuses on a few broad aggregates summarizing activity in the economy as a whole-nominal and real income, the inflation rate, and the unemployment rate.

New-classical economics has been undeniably influential, but not in the way that its three prominent creators originally imagined. Its most important contribution to macroeconomics, the assumption of rational expectations, was stolen almost immediately, and applied more fruitfully, by the new Keynesians.