New energy demonstration city, spatial spillover and carbon emission efficiency: Evidence from China's quasi-natural experiment

The new energy demonstration city (NEDC) are conducive to developing and applying renewable energy, reducing carbon emissions effectively, and reshaping the urban economic development model. Therefore, evaluating the impact of NEDC on carbon emission efficiency is of great significance to this policy's development and improvement. This study selected 278 cities in China from 2003 to 2017 to explore the influence and the response mechanism of NEDC on carbon emission efficiency through the spatial difference-in-difference model (SDID). The result shows that NEDC not only significantly promotes the local carbon emission efficiency but also improves the carbon emission efficiency of the surrounding cities within 1000 km. Meanwhile, it promotes urban carbon emission efficiency through optimizing industrial structure, stimulating green technology innovation, and reducing energy intensity, among which the impact of green technology innovation was the strongest. Furthermore, the direct effect of NEDC on carbon emission efficiency is more significant in western, non-resource-based, non-industrial, and large cities in China. The radiation effect of NEDC has already appeared in eastern China, but the spatial spillover effect in large cities has not yet occurred. These findings will help further promote NEDC and provide important decision-making references for urban energy conservation and emission reduction.