Socio-technical pathways of automotive decarbonization: evidence from patent network analysis in Germany and Japan

This paper examines how distinct institutional configurations shape divergent automotive decarbonization pathways in advanced economies. Drawing on the multi-level perspective (MLP) and patent-based network analysis, it compares Germany and Japan, two leading automotive producers facing similar global decarbonization pressures but pursuing markedly different transition strategies. Using patent co-classification networks (2012-2023), the study maps the structure and evolution of technological niches and their integration into incumbent socio-technical regimes. The findings reveal two contrasting transition pathways. Germany follows a policy-driven, EU-aligned, substitution-oriented trajectory centered on battery electric vehicles. This pathway is characterized by modular innovation structures and rapid regime destabilization, but is accompanied by heightened risks related to labor adjustment and supply-chain dependence. Japan, by contrast, pursues an industry-led, reconfiguration pathway based on technological diversification across hybrid, battery electric, and fuel-cell vehicles, supported by dense innovation networks and strong state-industry coordination. This pathway prioritizes gradual regime adaptation and transition resilience over rapid substitution. By linking patent network structures to transition pathway dynamics, the paper advances sustainability transitions research in two ways. First, it demonstrates how institutional embeddedness conditions the balance between transition speed and resilience. Second, it shows that technological diversification can function as a stabilizing mechanism in regime transformation rather than a factor of transition delay. The findings underscore the need for context-sensitive transition governance and caution against one-size-fits-all decarbonization strategies in mobility transitions.