A Study on the Impact of Cross-Border E-Commerce Development on New-Quality Productivity in Cities—A Quasi-Natural Experiment Based on Cross-Border E-Commerce Comprehensive Pilot Zones

提升新质生产力是推动经济高质量发展的关键，跨境电商作为数字贸易新业态，对新质生产力的影响值得深入研究。以2009~2022年中国275个地级市为对象，基于跨境电商综试区试点城市形成准自然实验，探讨该政策对新质生产力的影响及其作用机制。研究发现，跨境电商综试区政策显著提升了城市新质生产力，这一结论在控制高阶固定效应、缩短样本时间等一系列稳健性检验后依然成立。机制检验表明，跨境电商综试区通过促进技术创新进而提升新质生产力，验证了技术创新的中介效应。异质性分析发现，跨境电商对新质生产力的影响在经济发展水平高的地区更显著。基于此，建议构建跨境电商创新发展生态，完善数字化基础设施建设，深化制度创新，为新质生产力提升创造良好环境。Enhancing new-quality productivity has emerged as a critical driver for high-quality economic development. As an innovative form of digital trade, cross-border e-commerce (CBEC) warrants comprehensive investigation regarding its potential to foster new-quality productivity. This study leverages a quasi-natural experiment based on CBEC comprehensive pilot zones, examining 275 prefecture-level cities in China from 2009 to 2022. Employing a multi-period difference-in-differences approach, our empirical analysis reveals that the implementation of CBEC pilot zone policy significantly enhances urban new-quality productivity. This finding remains robust across various specifications, including higher-order fixed effects controls and alternative sample periods. Through mechanism analysis, we identify technological innovation as a crucial mediating channel through which CBEC pilot zones promote new-quality productivity. The heterogeneity analysis reveals that the impact of cross-border e-commerce on new-quality productivity is more pronounced in regions with higher levels of economic development. These findings carry important policy implications, suggesting the need to cultivate innovative CBEC ecosystems, strengthen digital infrastructure, and advance institutional reforms to create an enabling environment for new-quality productivity enhancement.