Can Urban "Gold Signboards" Yield Carbon Reduction Dividends? A Quasi-Natural Experiment Based on the "National Civilized City" Selection

As a crucial lever for urban governance transformation, city branding not only strengthens urban identity and attracts external capital but may also drive green and low-carbon transformation through reputational effects. However, existing research has paid limited attention to the impact mechanisms of city brand value on carbon reduction. Based on this, using a sample of 262 prefecture-level and above cities in China from 2002 to 2022, this article analyzes the impact of city branding on carbon productivity (CPR) through a multi-period difference-in-differences model based on the quasi-natural experiment of "National Civilized City" selection. Results show that the city branding initiative of National Civilized City can enhance CPR. The findings remain robust after parallel trend tests, placebo tests, and controlling for other policy interventions. Heterogeneity analysis indicates that the impact of National Civilized City branding on CPR is more pronounced in cities with superior geographical locations, higher brand dependence, and relative brand scarcity. Mechanism analysis reveals that National Civilized City branding can improve urban CPR by optimizing energy consumption structure, promoting technological progress, and increasing labor productivity. The research conclusions provide policy insights for deepening understanding of the emission reduction effects of city branding and expanding urban low-carbon development pathways.