The Metabolic Function of Digitalization: Chinese City-Level Evidence from the Efficiency Enhancement Perspective

As key hubs of resource consumption, cities play a critical role in advancing sustainable development through improved metabolic efficiency. This study, using panel data from 287 Chinese cities between 2011 and 2021, employs the unexpected output SBM model to assess urban metabolic efficiency and examines how it is driven by digital economy growth. Results reveal a gradual but uneven improvement in the metabolic efficiency of Chinese cities, with significant regional disparities underscoring imbalances in resource use and economic progress. Notably, digital economy development significantly enhances urban metabolic efficiency, a conclusion that remains robust after controlling for endogeneity and robustness issues. Mechanism analysis indicates that industrial upgrading and technological advancements are key drivers of this improvement. Furthermore, enhancing network infrastructure further accelerates metabolic efficiency in the context of the digital economy. Heterogeneity analysis reveals an asymmetric impact, with more pronounced effects in eastern regions, major cities, less educated populations, and non-resource-based cities. The study also identifies a threshold effect, whereby the positive influence of the digital economy becomes evident only after reaching a certain level of development, and this effect exhibits increasing marginal returns over time. These findings provide empirical support for leveraging the digital economy to enhance urban metabolic efficiency in China and offer insights for global urban sustainability strategies.