elsewhere (1982), economists' beliefs that modern capitalism is a fine innovation-generating machine have no intellectual grounding in contemporary neoclassical theory. The twin theorems take technologies as given. The apparent effectiveness of capitalism in this arena must reside in characteristics and mechanisms other than those featured in the microeconomic theory textbooks. In our book, we attempt to analyze these. It also is true that the capitalist engine is a much more complicated one than many economists seem to think. I presently am

In nursing this essay through several drafts, I have benefited greatly from suggestions by Edward Denison, Robert Evenson, Zvi Griliches, Richard Levin, John Kendrick, Edwin Mansfield, and Richard Murnane. Moses Abramovitz has been a source ofencouragement and good, substantive editorial advice, for which I am most grateful. The heterodox views are my own, although I share many of them with Sidney Winter.