Roles of related and unrelated external technologies in shaping regional breakthrough technological advantages

Technological innovation serves as an intrinsic driver for regional economic development, particularly wherein breakthrough innovations exert a profound impact on the continuous evolution of regional technologies and industrial upgrading. Given the uneven distribution of innovation resources and technological capabilities across regions, regions should not only focus on indigenous innovation but also consider how to leverage knowledge from outside the region. This approach is crucial for breaking the path dependency of innovation to achieve regional technological breakthrough. Our paper broadens the technological relatedness framework from a local scope to an inter-regional context by introducing the concept of external technological densities. Specifically, we investigate the nuanced roles of external technologies distinguished by relatedness and unrelatedness, in shaping the trajectories of regional breakthrough technological innovation. Our research underscores the crucial role of assimilating knowledge spillovers from related external technologies for catching-up regions, as such integration fosters breakthrough innovations, while the inclusion of unrelated external technologies exhibits adverse effects. Moreover, both external identical technology and external related technology complement local related technology, jointly facilitating breakthroughs in relative technological advantages. However, in high-complexity cities and technological domains, it is more critical to leverage local related and unrelated technologies rather than relying on external knowledge spillovers.