A Study on Agglomeration Externality and Spatial Convergence of Carbon Productivity

From the perspective of new economic geography,the paper puts the agglomeration externalities into the framework of spatial convergence of carbon productivity. The results indicate that: carbon productivity between neighboring regions has characteristics of viscosity and clustering. Whether in the long term or in the short term,carbon productivity presents the effect of βconditional convergence and‘club'spatial convergence. The eastern provinces benefit from the positive externalities of neighboring provinces significantly and converge to a higher value,while the midwestern provinces are affected by the negative externalities of neighboring provinces and converge to a lower value. Agglomeration externality is an important mechanism to improve carbon productivity and promote convergence. Different forms of agglomeration correspond to different carbon productivity. With the improvement in the level of agglomeration,the effects of specialized agglomeration decreases while diversified agglomeration increases.The emission reduction of specialized agglomeration and diversified agglomeration depends on the proper degree of agglomeration. The emission- reduction effects of specialized agglomeration and diversified agglomeration are significant in the eastern region,while the midwestern regions only reflect the weak specialized agglomeration effect. Empirical studies shows that the agglomeration production is better than the decentralized production in improving the efficiency of carbon emission. The government should take different industrial agglomeration forms and policies according to the different degrees of agglomeration and industrial development stage.