The central purpose of this book may be simply stated. Economists have long treated technological phenomena as events transpiring inside a black box. They have of course recognized that these events have significant economic consequences, and they have in fact devoted considerable effort and ingenuity to tracing, and even measuring, some of these consequences. Nevertheless, the economics profession has adhered rather strictly to a self-imposed ordinance not to inquire too seriously into what transpires inside that box.

The purpose of this book is to break open and to examine the contents of the black box into which technological change has been consigned by economists. I believe that by so doing a number of important economic problems can be powerfully illuminated. This is because the specific characteristics of certain technologies have ramifications for economic phenomena that cannot be understood without a close examination of these characteristics. Thus, I attempt to show in the following pages how specific features of individual technologies have shaped a number of developments of great concern to economists: the rate of productivity improvement, the nature of the learning process underlying technological change itself, the speed of technology transfer, and the effectiveness of government policies that are intended to influence technologies in particular ways.