Innovation Capability and Network Evolution of China's New Energy Vehicle Industry from a Policy Chain Perspective

The New Energy Vehicle (NEV) industry is key for the transformative development of China's automotive industry, with policy chains, market scale, and technological innovation serving as critical drivers of its innovation network. To provide scientific support for enhancing independent innovation capabilities and achieving sustainable development in China's NEV industry, this study analyzes policy portfolios and patent collaboration data using Social Network Analysis (SNA) and Vector AutoRegression (VAR) models and investigates the mechanisms through which policy chains shape the innovation network, with a focus on how policy interventions influence collaborative innovation dynamics and spatiotemporal evolution patterns. The results indicate that: (1) China's existing policy chain system exhibits short-term positive effects on enhancing the innovation capabilities of the NEV industry, primarily driven by fiscal subsidies, tax incentives, and pilot demonstration projects. However, these effects diminish over time. (2) Significant spatiotemporal disparities in innovation development have emerged due to the influence of policy chains and regional differences in resource allocation, economic foundations, and innovation environments. Developed eastern regions, supported by mature industrial clusters, were found to demonstrate higher policy responsiveness, whereas the central and western regions lagged in translating policy inputs into innovation outputs. (3) The spatial structure of the innovation network transitioned from a triangular pattern to a diamond-shaped framework with multiple core regions, reflecting the holistic evolution of collaborative relationships under policy guidance. This study makes the following key contributions: (1) systematically categorizing the major direct policies of China's NEV industry into vertical and horizontal policy chains and constructing a comprehensive policy chain framework applied to the analysis of the development of the NEV industry's innovation collaboration network; (2) contributing to theoretical discussions on innovation network research regarding knowledge flows, inter-entity collaboration, and innovation environment shaping by proposing a "policy chain–innovation network" coupling framework that links macro-level governance with micro-level collaborative behaviors. Consequently, future policy design for China's NEV policies must undergo a paradigm shift. Policymakers should prioritize a systematic, adaptive, and forward-looking approach to construct a multilevel policy chain system that balances short-term stimulation with long-term capacity building. To stimulate endogenous innovation vitality within enterprises, it is essential to accelerate the transition from government-led subsidy policies to market-oriented competition. Simultaneously, spatially differentiated policies should be implemented and tailored to local innovation environments to address regional development disparities. This includes increasing support for infrastructure investments and talent mobility programs in the central and western regions to narrow the innovation capability gap between the regions. By promoting a shift from industry-supportive to competition-driven policies, a market-friendly policy environment can be established that enhances the market's role in selecting technologies, products, and services. This approach ultimately fosters the synergistic development of policy chains and sustainable innovation ecosystems.