Jacobian spillovers in environmental technological proximity: the role of Mahalanobis index on European patents within the Triad

The aim of this paper is to investigate the role of Jacobian externalities stemmed from different technological sectors for international firms engaged both in environmental and in dirty activi- ties. Firms’ innovation, measured, as the development of new patents, is a key factor behind the achievement of desired economic performances. Empirical literature usually deals with the inte- gration between ecological efficiency and product value enhancement. The results of these stud- ies lead to the lack of integrated innovation adoption behind environmental productivity per- formance. In this work, we analyse the integration between more environmental goals in an original way, by applying different methodologies to compute technological proximity, based on the Mahalanobis approach. To this end, we use information from 240 large international firms, located in three economic areas: USA, Japan and Europe and we select their environmental and dirty patents from European Patent Office data