The chapters that comprise this book were written over a ten-year period running from the early 1960s to the early 1970s. They had their origin in my interest in long-term economic growth processes, especially the behavior of industrializing societies. The form and directions these chapters have taken reflect two basic influences: (1) the growing awareness of the centrality of technological phenomena in generating economic growth, an awareness that had been sharply reinforced for economists by the publication of two articles by Moses Abramovitz and Robert Solow in the mid-1950s; (2) a growing sense that, in spite of the basic orientation and genuine insights into technological phenomena provided by the neoclassical economics in which I had been trained, a deeper and richer understanding of these phenomena would involve a willingness to step outside of the limited intellectual boundaries of this mode of reasoning. In the course of this pursuit, I suppose it is fair to say that I became an economic historian, a very amateurish historian of technology, and an avid (but highly selective) reader of the literature of neighboring disciplines. With apologies to Clemenceau it might be said that if technological change is not too important a subject to be left to the economist, it certainly is too diverse a subject to be left to the economist who refuses to step across narrow disciplinary boundaries. I hope that these chapters will offer some modest demonstration of the potential rewards to such intellectual trespassing.

Technological change encompasses, of course, a highly complex and wide-ranging collection of human activities. Moreover, not only do technologies change over time, but there are, in fact, numerous technologies that coexist in a society at any moment.