The Impact Of Urbanization On China's Carbon Emission Efficiency

Urbanization is an important feature of China's economic development in current stage. Carbon emission reduction has a profound impact on the long-term and sustainable development of China's economy and society, it also represents an important responsibility for world environment and climate change, which is committed by the Chinese government. Encountered by China's rapid development of the new urbanization, it is of great value to discuss the impact of urbanization on carbon emission efficiency(CEE), this study will help to seek a path of coordinated development between China urbanization process and carbon emission reduction, it will also help to optimize the urbanization mode and environment policy. According to the urban environment transition theory, which is proposed by Poumanyvong and Kaneko, urban environment have different characteristics with the change of urbanization stage, carbon emission problem associated with industrial pollution is more significant in lower urbanization stage, and the carbon emission problem, which is related to energy consumption, will be more significant in higher urbanization stage. Theoretically, the impact of urbanization on CEE depends on the trade-off between the decline of CEE, which is caused by the growth of total carbon dioxide(CO2) emissions, and the increase of CEE, which is caused by the growth of energy consumption efficiency. Moreover, the impact of urbanization on CEE depends on the indicators of urbanization, intermediate transmission factors, time factors and other external factors. Therefore, this paper analyzes the internal impact mechanism of urbanization on CEE, and studies the relationship between urbanization and CEE according to the status quo of China's urbanization process and the provincial CO2 emissions.Firstly, CEE is defined by the ratio of the optimal carbon emission and the actual carbon emission, then CEE is embedded into the Stochastic Impacts by Regression on Population, Affluence and Technology(STIRPAT) model, which is proposed by Dietz and Rosa, and the extended model is employed to estimate the direct impact of urbanization on CEE. This paper analyzes the impact of urbanization on CEE from the perspective of economic growth, industrial structure adjustment and consumption upgrading. On the one hand, these intermediate factors will enhance the total energy consumption and CO2 emissions in the process of urbanization, on the other hand, these factors will inhibit the growth total CO2 emissions via the promotion of cleaner production and the increase of energy efficiency. The impact of urbanization on CEE depends on the trade-off between these two aspects. Motivated by the urbanization model(Black and Henderson, 1999) and pollution model(Stocky, 1998), this paper uses a framework of optimization theory to analyze the channels of urbanization—human capital accumulation and clean production—which would significantly affect the impact of urbanization on CEE. The theoretical model indicates that urbanization promotes enterprises to choose cleaner production technology, this preference is long-term and effective. Meanwhile, urbanization is conducive to the growth of human capital of urban residents, and the improvement of human capital accumulation is helpful to the application of cleaner production technology in economic sector, which can lead to carbon emission reduction and the improvement of CEE. Both human capital accumulation and cleaner production are the channels for the impact of urbanization on CEE, both of these channels can reduce the marginal impact of urbanization on CO2 emissions, weaken the negative influence of total CO2 emissions on CEE, which will lead to the improvement of CEE.Based on the IPCC(2006) calculation method, this paper estimates the data of China's provincial CO2 emissions, originating from fossil fuel burning and cement production. Then CO2 emissions is embedded into the production set in the form of undesirable output. According to the directional distance function proposed by Chung, the slack based model(SBM) and the DEA window analysis, this paper estimate China's provincial CEE index during the period of 1995-2012. This paper constructs a set of environmental production technology, including four elements which is named as labor, capital stock, GDP(desirable output) and CO2 emissions(undesirable output). Each window width is set to three years in DEA window analysis. DEA window analysis indicates that CEE shows periodic variation in the national sample and the three regions' samples. CEE in the eastern region is higher than that in the central and western regions, and the overall changes in the eastern region is relatively stable. CEE in the central and western regions show a continuous decreasing trend after 2000, and CEE in the western regions is lower than that in the central regions. Meanwhile, the panel clustering analysis and spatial maps are also employed to exhibit the clustering and spatio-temporal characteristics of China's provincial CEE.Based on the theoretical analysis, this paper constructs an econometric equation to estimate the impact of urbanization on CEE. By using dynamic panel estimation method, panel error correction model and panel threshold model, this paper empirically studies the relationship between China's urbanization process and provincial CEE from the perspective of time factor, intermediate transmission factors and external factors. Empirical results show that both of the urbanization indices display positive effects on the actual CO2 emissions and the optimal CO2 emissions. Urbanization of household registration population has a positive effect on CEE, but urbanization of resident population has a negative effect on CEE, the potential factors are China's urban population structure and interprovincial population migration. The results of panel error correction model indicate that the short-term effect is negative between urbanization of household registration population and CEE, while the long-term influence coefficient is positive, indicating that urbanization of household registration population is helpful to the improvement of CEE in the long term. As for the regression results from the channels of human capital accumulation and cleaner production, the impact of urbanization rate of household registration population on CEE is uncertain, while urbanization rate of resident population has a robust negative influence on CEE. Human capital accumulation weaken the negative impact of urbanization on CEE, and cleaner production weaken the negative impact of urbanization of resident population on CEE. The panel threshold model proposed by Hansen is employed to test the interval effect of population migration on the relationship between urbanization and CEE. The results prove the existence of a significant single threshold effect. With the growth of proportion of temporary population, the positive effect of urbanization of household registration population on CEE increases gradually, while the negative effect of urbanization of resident population on CEE decreases gradually.Finally, by using the kernel density estimation, Gini coefficient and theil index method, this paper examines the dynamic evolution and regional differences of China's provincial CEE, the result indicates the gap of interprovincial CEE shows a gradually increasing trend. Based on the ? convergence model proposed by Barro and Sala-i-Martin, this paper tests the convergence characteristics of China's provincial CEE. The results show that there is a significant ? absolute convergence of China's provincial CEE during the sample interval before 2005. However, CEE shows divergent behavior during the sample interval after 2006. There is significant club convergence behavior of provincial CEE in the eastern regions during the sample interval before 2005, while the club convergence behavior disappear during the sample interval after 2006. Provincial CEE in the central regions and the western regions don't exist club convergence behavior. The results of panel threshold model indicate there is a significant single threshold effect of interprovincial urbanization gap on the convergence of CEE. With the gradually increasing urbanization gap, the convergence trend and speed of provincial CEE are gradually weakened.