Harrod on the classification of technological progress. The origin of a wild-goose chase

From the 1930s to the 1970s many economists debated the classification of technological progress into neutral, labour- or capital-saving inventions. One of them was R.F. Harrod, who defined neutral inventions as those in which the capital-output ratio remains unaffected at a certain rate of interest. The present work examines the origin and development of Harrod’s notion of neutrality, illustrating how it was characterised, what conceptual framework it presupposed, and what function it played within his dynamic economics.