The impact of the urban digital economy on China's carbon intensity: Spatial spillover and mediating effect

The development and expansion of the digital economy, including the internet, big data, and cloud computing, provide a new impetus to reaching peak carbon emissions and achieving carbon neutrality. However, the impact and mechanism of the urban digital economy on carbon intensity are still insufficiently characterized. This study confirms a significant inverted U-shaped relationship between them by adding a quadratic term and conducting a U test. When the index of the digital economy exceeds 0.419, it reduces carbon emissions intensity. The empirical results indicate that the digital economy has a nonlinear spatial spillover effect on the carbon emission intensity of adjacent cities presenting a U-shape. The digital economy can not only directly affect carbon emission intensity, but also indirectly affects it by optimizing industrial structure and promoting scientific and technological innovation. The methodology of this paper can be used for future research, and the findings can support the regional development of the digital economy and the formulation of carbon reduction policies.