Two-stage dynamic StoNED model for efficiency evaluation of green technology innovation: evidence from a cross-country study
摘要
Despite the growing body of research on green technology innovation efficiency, existing studies predominantly focus on single-country analyses or static frameworks, neglecting systematic cross-country heterogeneity and dynamic inter-stage synergy within the macro-innovation ecosystem. To accurately diagnose the structural bottlenecks of global green transition, this study conducts a cross-country comparative research driven by a methodological innovation. Specifically, building on the innovation value chain theory, this study constructs a novel two-stage dynamic stochastic nonparametric envelopment of data (StoNED) model. Unlike traditional deterministic models, this framework uniquely accommodates both statistical noise and nonparametric frontier flexibility, enabling a more robust inter-temporal evaluation of the R&D and production stages. Furthermore, a coupling coordination degree (CCD) model is integrated to evaluate the systemic synergy between stages. Incorporating the R&D time lag, this study utilizes 2007–2019 panel data from 39 countries to measure the two-stage efficiency for the 2007–2018 period. The results reveal: (1) Significant cross-country heterogeneity exists in efficiency distribution. Countries are classified into four distinct profiles (Dual-high synergy, R&D-driven, Double-low, and Production-driven). Notably, massive R&D capabilities in major economies often coexist with lagging production efficiency, highlighting the “technology-institutional complex locking” effect as a key bottleneck in the commercialization process. (2) Dynamically, while R&D efficiency rises steadily, production efficiency exhibits an “inverted U-shaped” trajectory that highly synchronizes with global energy price fluctuations. (3) The overall systemic coordination reveals a tiered global landscape, demonstrating that sustainable green innovation relies on balanced inter-stage coherence rather than single-stage superiority. By advancing the dynamic StoNED-CCD framework, this study enriches the methodological literature and provides critical insights for designing differentiated, dynamically adjustable green technology policies globally.