U-shaped relationship between digitalization and low-carbon economy efficiency: Mediation and spillover effects

Digitalization has been widely deemed as a catalyst for economic growth and efficient, sustainable production, yet the impact and mechanism of digitalization on low-carbon economy efficiency (LCEE) remain elusive. This study constructs a comprehensive metric to assess digitalization development level and applies the super-SBM model to quantify LCEE. Based on panel data from 264 Chinese cities spanning 2008 to 2020, this study examines the direct effect of digitalization on LCEE using a bidirectional fixed-effects model, and explores the mediation and spillover effect using the mediation effect test model and spatial Durbin model, respectively. Several key findings are identified : (1) There is a U-shaped relationship between digitalization and LCEE, signifying an improvement in LCEE when the index of digitalization surpasses 1.488; (2) The impact of digitalization on LCEE is mediated by industrial structure upgrading and green technological innovation, presenting inverted U-shaped and U-shaped patterns, correspondingly; (3) The spatial spillover effect of digitalization on LCEE shows an inverted U-shaped; (4) The promotion effect of digitalization is more pronounced in the dimension of digital innovation, western region and cities endowed with network infrastructure. These findings provide rich insights for policymakers to formulate urban digitalization development and carbon reduction measures.