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geographical distribution of patenting activity and illustrating the social networks of each
field from co-authorship relationships. While observing gross innovation trends in clean
technologies, we also focus our analysis on the source of commercial and technical
breakthrough innovations. In particular, it is important to focus on these valuable
innovations as unique from bulk patenting trends because most patents are useless or of
moderate value [33], as opposed to breakthroughs that significantly change the landscape
of technological or business practice. The impact of inventions is then measured in each
technology field through two proxy measurements of each patent, technical impact (as
measured by future citations) [34], and societal and commercial influence (as quantified
by a novel measure of Web presence introduced in this manuscript). These dependent
variables enable estimations of the impact of social, institutional, and geographical
influences upon the processes of invention for each technology. In the final section of
this paper, we provide hypotheses to explain these differences along with a research
agenda that we hope can inform policy suggestions.

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