Does vertical integration enhance technological innovation? Evidence from China's energy-related metals supply chain

Driven by the dual imperatives of resource security and technological upgrading, countries worldwide are accelerating the construction of renewable energy–related metals supply chains, exemplified by the integration of non-ferrous metals and renewable energy manufacturing sectors. This process has triggered a new wave of vertical integration among enterprises. However, whether vertical integration strategies can effectively enhance technological innovation acrosssupply chains remains a topic of theoretical debate and empirical uncertainty. To assess the effectiveness of this strategy, we conducted a specialized study of non-ferrous metal and renewable energy manufacturing enterprises listed on China's A-share market during the period 2009–2024, adopting an supply chain perspective. The findings reveal:Vertical integration has become an important strategic choice for firms along the energy-related metals supply chain in the context of energy transition. Empirical results indicate that vertical integration is positively associated with firms technological innovation performance, operating mainly through enhanced organizational stability and more efficient resource allocation. The innovation-enhancing effect is stronger for forward integration led by non-ferrous metal enterprises than for backward integration implemented by new energy firms. Moreover, this effect is amplified under conditions of larger supply–demand mismatches, higher levels of digital transformation, lower financing constraints, and within state-owned enterprises. The research findings offer a reference for decision-making in the non-ferrous metal industry, therenewable energy industry, and other strategic emerging industries seeking to explore patterns of technological innovation.