Keynesian, New Keynesian and New Classical Economics.

Formal developments of the Keynes's General Theory, while attempting to achieve a new classical synthesis of the realities of observed macroeconomic fluctuation and unemployment with classical microeconomics, have come to be surprisingly closely tied to the old classical models. Keynes's insights have been reduced largely to an assumption of nominal price rigidities. In fact, Keynes's original qualitative approach contained a much richer description of economic reality. This paper describes how fully rational microeconomic models incorporating imperfect information and incomplete markets, very much in the Keynesian tradition, imply macroeconomic behavior that encompasses most of the qualitative insights of the General Theory. Copyright 1987 by Royal Economic Society.