| With the deepening of economic globalization,the increasingly serious issue of climate change has posed a great challenge to all countries in the world.How to deal with the relationship between economic development and climate change is of great significance for the early achievement of the Sustainable Development Goals（SDGs）,especially for the countries along the Belt and Road,which are generally at the lower end of the global value chain and face the problem of trade and environmental imbalance.In order to prevent the domestic economy from falling into the“middle-income trap”and to mitigate the threat of international climate change,China has proposed the“Belt and Road”initiative for the first time and promoted the economies of the countries along the route to move towards high-quality development.The high-quality development of trade is an important part of the high-quality development of the economies along the route,and the upgrading of the export structure is the basis for the high-quality development of trade.However,the“low quality”export trade structure not only aggravates the growth of CO2emissions,but also is not conducive to the transformation of domestic economy and the achievement of sustainable development goals.To this end,exploring the impact of the transformation of export structure on carbon emission efficiency of the countries along the route can not only achieve a win-win situation of sustainable economic development and energy saving and emission reduction,but also make an important contribution to promote the high-quality development of“One Belt,One Road”.This study investigates the impact of export trade structure on carbon emission efficiency in countries along the“Belt and Road”route through a combination of normative and empirical analyses based on international trade theory,new growth theory and intellectual property rights system.The main contents and innovations of this study include the following.First,based on the theory of environmental effects of international trade,the possible direct effect of export sophistication of high-tech products on carbon emission efficiency is proposed.Based on the vertical spillover effect,“learning by exporting”effect and human capital theory,we hypothesize that the export sophistication of high-tech products can achieve carbon emission reduction indirectly through the height of industrial structure,the level of technological progress and human capital accumulation,and empirically test the mechanism of the effect using the benchmark model and compound multiple mediating effect model.Thus,this study innovatively unveils the“black box”mechanism of the impact of export sophistication of high-tech products on carbon emission efficiency.Not only the direct impact of export sophistication of high-tech products on carbon efficiency is significant,but also the indirect impact path of export sophistication of high-tech products on carbon efficiency is also explored and found.The three aspects of the structural upgrading effect,technological progress effect and skill effect of export sophistication of high-tech products are analyzed,and it is confirmed that the height of industrial structure,the level of technological progress and human capital accumulation play parallel mediating roles and chain mediating roles.Secondly,considering the protection of intellectual property rights is an important institutional factor affecting the quality of export products.This paper explores the moderating role of IPR incentives between export sophistication of high-tech products and mediating variables and the boundary conditions of IPR protection in the indirect path based on public goods theory and cohort effects,and therefore conducts an empirical test using the moderated mediating effects model.Thus,this study indicatively analyzes the boundary conditions of the environmental effects of strengthening IPR protection on the country’s export trade,and finds that the higher the level of IPR protection,the more significant the structural upgrading effect,the technological progress effect and the skill effect of export sophistication of high-tech products,and the more conducive to achieving carbon emission reduction.Finally,in order to fully analyze the impact of export sophistication of high-tech products on carbon emission efficiency,the interaction between export sophistication of high-tech products and carbon emission efficiency is further investigated through the construction of a panel vector autoregressive model,using impulse response function and variance decomposition analysis.Thus,this study indicatively analyzes the internal logic of the interaction between export sophistication of high-tech products and carbon emission efficiency,providing a new perspective to deepen the two-way interaction between them and deepen the research in related fields.It is found that there is a significant mutually reinforcing effect between the two,i.e.,Improving the export sophistication of high-tech products helps to improve carbon efficiency,and the improvement of carbon efficiency will further promote the export sophistication of high-tech products.Based on the clarification of relevant concepts,theories and hypotheses,this study analyzes the influence mechanism,boundary conditions and dynamic interaction of export sophistication of high-tech products on CO2emissions using a benchmark model,a composite multiple intermediary model,a moderated intermediary model and a panel vector autoregressive model.This study not only supports the strategic trade policies of the countries along the Belt and Road to expand the export of high-technology products,but also provides a reference for achieving carbon emission reduction targets,mitigating climate change and promoting the United Nations Sustainable Development Goals. |
