The first edition of The Sources of Invention, published in 1958, has been described as "a classic in science policy which has had a very considerable influence on both economists and scientists in Europe and in the United States." The authors set out to study the causes and consequences of industrial innovation--one, if not the main, spring of economic progress. They examined the important inventions of the nineteenth and twentieth centuries in order to discover just how far recent inventions have emerged from conditions different from those of the past. The evidence collected...