Efficiency and convergence of China's export trade embodied carbon emissions

Based on the input-output data from 2002 to 2017, this paper combined the three-stage DEA model with the non-competitive I-O model and measured the embodied carbon efficiency of export trade in China ’ s 26product sectors, and further investigated its influencing factors and convergence issues. The results of the study showed that:(1)The embodied carbon efficiency of export trade in China ’ s overall product sector demonstrated a positive development trend from 2002 to 2017, and this positive trend was more obvious after the implementation of conservation culture construction in 2012. But the differences of embodied carbon emission efficiency level among the product sectors were still significant.(2)Measured by the K-means clustering analysis method, this study found that agriculture, other service industries, wholesale and retail industries, catering industry, construction industry and manufacturing industry with strong innovation ability were mostly concentrated at high and medium efficiency levels, while industrial sectors with resource dependence and high energy consumption, such as metal smelting and rolling processing industries, nonmetallic mineral products industry, and coal mining industry, were at a low efficiency level.(3)All product sectors had σ convergence, absolute β convergence and conditional β convergence during 2002 – 2010 and 2010–2017, and the level of each product sector in 2010–2017 was higher than that in 2002–2010 according to the perspective of convergence speed and degree of convergence.(4)Technological progress had not fully played a role in suppressing energy consumption and improving the efficiency of embodied carbon efficiency, and it would also widen the gap between the embodied carbon emission efficiency levels of various product sectors. The expansion of trade scale could effectively improve carbon emission efficiency and narrow the gap between sectors. Environmental regulation could effectively promote the improvement of embodied carbon emission efficiency but would widen the level gap between sectors. These findings indicate that China needs to build a sound environmental regulation system for the development of low-carbon trade, continue to reasonably expand the scale of trade, eliminate backward industries with production capacity, vigorously develop low-carbon technologies such as new energy, strengthen the exchange of lowcarbon technologies and industrial cooperation among sectors, and promote coordinated development among industries.