Inventing modern invention: the professionalization of technological progress in the US

As invention in the US shifted from craftsmanship to a science-based activity in the early 20th century, profound changes happened in the production of knowledge. Using historical records on the universe of inventors, and research laboratories, matched to decennial census records between 1850 and 1940, we find that as inventions start becoming more complex (combining more technologies) and innovative (using increasingly newer technologies), they reflect qualitative shifts in how individuals, teams and geography produce knowledge that persist until today.