Investigating the impacts of technological position and European environmental regulation on green automotive patent activity

Using patent data on 355 applicants patenting to the European patent offices from 1998 to 2010 on environmental road transport technologies, we investigate under what conditions the European environmental transport policy portfolio and the intrinsic characteristics of assignees’ knowledge boost worldwide green patent production. Our findings suggest that post-tax fuel prices, environmental vehicle taxes, CO2 standards and European emission standards, introduced in the empirical model through an innovative methodology based on Self-Organising Maps (SOM) (Kohonen, 1990; 2001), positively influence the creation of environmental inventions. Most importantly, we advocate that assignees anticipate the introduction of those emission standards, filing patents before the effective implementation of regulations when legislations are announced. Furthermore, we provide evidence that in a technological space (which measures the applicants’ technological proximity), closely located organisations enhance their patent output through the exploitation of technological knowledge produced by others. This means that the greater the proximity between assignees, the higher their likelihood of taking advantage of the knowledge produced by others. Finally, we observe that dynamic changes (both in quantity and in the number of technological fields engaged) in assignees’ patent portfolios spur inventive performances.