Patents on General Purpose Technologies: Evidence from the Diffusion of the Transistor

How do patents influence the spread of General Purpose Technologies? To answer this question, we analyze the diffusion of the transistor, one of the most important technologies of our time. We show that the transistor diffusion and cross-technology spillovers increased dramatically after AT&T began licensing its transistor patents on standardized terms in 1952. This suggests that standardized licensing of the transistor patents helped jumpstart the positive feedback loop between innovations upstream and in applications. A subsequent reduction in royalties did not lead to a further increase, suggesting that standardized licensing in itself is more important than the specific royalty rates.