增长、就业及减排目标约束下的产业结构优化研究

Optimal Industrial Structure with Carbon Emission, GDP Growth and Employment Targets

该研究建立了投入产出框架下的产业结构优化模型,在减排目标、GDP增长率、就业率的多重约束条件下,测算了中国实现国民经济最小波动的最优产业调整路径,揭示了低碳经济与可持续发展下应当鼓励和控制发展的重点行业:产值提升最大的应包括批发零售贸易、公共与居民服务业、机械电气设备制造维修业、住宿餐饮业等排放系数较低且最终需求水平较高的行业,产值下降最大的则是电力热力生产和供应业、金属冶炼及压延加工业、以及石油加工及炼焦燃气等,这些行业无疑是实现国家在稳定增长前提下减排目标的关键。通过调整约束条件的强度,研究发现,随着碳减排约束的收紧、以及经济增长目标的提高,所需的产业结构调整幅度会逐渐增大,并且减排力度加强所要求的结构变动比经济增长率提高所要求的变动更大,因此对于中国经济未来发展,实现减排任务比片面追求GDP增长率难度更大、成本更高。由于模型解得的理论最优变动率普遍小于过去10-20年中国各行业的实际增长率,因此本研究提出的"降排放、保增长"的产业结构调整方案具有一定的现实可行性。尤其是第一产业和矿产开采业近10年的实际变动率已经接近模型求解的最优调整方案,但是大多数行业的实际增长值要远超过理论最优值,所以适当放缓增长步伐,能够在保持适当的经济增长率与就业率的前提下,有效降低能耗及排放强度。

This study employs an input-output model to ascertain the optimal changes necessary in different industrial sectors of the Chinese economy required to achieve the carbon emission target, where constraints on GDP growth and employment rate are met as well. Industries which require the greatest reduction and increase in final demand are identified. Wholesale and Retail Trade, Health and Community Services, Machinery and Equipment Manufacturing, and Accommodation and Restaurants are required to achieve the largest increase in final demand; while the largest required annual rate of reduction in final demand is for Electricity and Gas Generation and Supply, Structural, Sheet and Fabricated Metal Product Manufacturing, and Petroleum Refinery. Those industries mentioned above are essential to China＇ s low-carbon economy with sustainable growth. As the constraints change, it is found that strengthening constraints requires greater adjustment in final demand, and achieving higher emissions target calls for greater adjustment in industrial structure than that required to achieve higher growth rates. As a result, cutting carbon emissions will be much more challenging and costly for China than simply seeking for high GDP growth in the future. When compared with annual actual sectoral growth in China in the past 10 to 20 years, the required alterations derived in the model are not large and thus attainable in reality. Therefore, the plan proposed by this study to achieve emission reduction as well as decent growth through adjusting industrial structure is feasible. Especially, the first industries and mining have already been growing at rates close to those solved by the model in this study, however, most other sectors are still experiencing far higher growth than the optimal ones proposed here. In this sense, slowing down a little bit would effectively reduce the country＇ s energy consumption and emission intensity in the meantime maintaining growth and employment rates at acceptable levels.