Green Technologies and diversity in the knowledge search and output phases: Evidence from European Patents

The aim of this study is to investigate technological diversity in the knowledge search and the knowledge output stages of the green inventive process. Exploiting a large sample of European patent data, from 1980 to 2013, the paper explores the degree of diversity in green inventions, comparing the recombinant features of green technologies with a control sample of non-green technologies selected through propensity score matching techniques. Empirical results suggest that green technologies show a higher degree of diversity of the knowledge sources and a higher technological diversity in how knowledge is effectively recombined. We further find that the green diversity premium is higher in the knowledge output phase than in the knowledge search phase. We conclude that the assessment of the role of technological diversity along the different phases of the invention process may improve the appropriate organization of innovative activities and policy design necessary for stimulating green technological developments and support a feasible sustainable transition.