technological change, knowledge sharing, collective invention, patents

N70, O33, O34

This chapter documents instances from past centuries where inventors freely shared knowledge of their innovations with other inventors. It is widely believed that such knowledge sharing is largely a recent development, as in open source software. Our survey shows, instead, that innovators have long practiced "collective invention", including in such key technologies as steam engines, iron and steel production and textile machinery. Generally, innovators? behavior was substantially richer than the heroic portrayal often found in textbooks and museums. Knowledge sharing sometimes coexisted with patenting, at other times, not, suggesting the importance of public policy that accommodates knowledge sharing to foster cumulative innovation.