Combining digital and green technologies in regions: How to close the gap with respect to the frontier?

This paper focuses on the combination of green and digital technologies at the regional level. Using patent data, we put forward an original measurement of the regional speed of a new green-digital (i.e. twin) combination: the temporal distance between the time at which a combination is realised for the first time in the frontier region and the time at which this same combination is accomplished in the focal region. We proceed by investigating the drivers and the technological impact related to this speed. We find that the speed of combination is enhanced by dealing with broad twin technologies and by recombining more diverse prior knowledge to do that. The speed at which the gap is closed, also crucially depends on the interdependencies between green and digital local domains, captured by the overlap in their regional knowledge bases. Counterintuitively, the longer their combination paths, the faster regions combine green and digital technologies. Finally, we find that the earlier the first regional green-digital combinations happen, the greater is their impact on subsequent inventions, while the impact of all regional green-digital combinations is apparently lower. Overall, these results are discussed in terms of policy recommendations, given the high attention placed by policymakers on the twin transition.