需求弹性是经济学中的基础概念,也是我国煤炭市场化进程中的重要研究对象。不同于以往的宽泛研究,本文分别从国家维度、时间维度和区域维度对1995—2010年间的我国煤炭需求弹性展开系统化研究。基于面板数据模型的研究发现全国煤炭需求的价格弹性为0.59,煤炭在所考察期间总体呈现出刚性需求现象,但基于截面数据的回归结果显示各考察年份的煤炭需求弹性为负值且存在着较大的时间波动,而各区域时间序列的回归结果表明煤炭需求弹性的区际差异:煤炭主产地其值为负,消费地其值为正。分析发现以国家维度和时间维度的研究结论相互矛盾,而以区域维度的研究结果更加科学合理,具有更为可靠的理论和现实指导意义。
Demand elasticity is a basic economic concept and widely used in large energy economic system models such as NEMS (national energy modeling system), MARKAL (market allocation) and ETSAP (the energy technology systems analysis program). Coal' s complete marketization in China commenced in 2013 and demand elasticity is now very important. Econometrics technology is often used to estimate China' s coal demand elasticity by different time series, but results vary. Here, we collected panel data from 1995-2010 and used different models to estimate price elasticity systematically in three dimensions: national level, time level and regional level. The results show that national price elasticity is 0.59, which means coal demand is rigid, lacks elasticity and price mechanisms have yet to affect this system. When demand elasticity is estimated by cross-section data using time, its values, which are contrary to the national level, are negative and vary among years according to the economic climate. This means that the supply- demand of coal obeys basic economic rules. Regression results based on regional levels are more reasonable and convincing since coal demand elasticity is negative in main production provinces and positive in main consumption provinces. The negative values in abundant resource provinces are larger than lower-resource provinces and positive elasticity in developed provinces is larger than undeveloped ones. We also found that differences in coal demand are related to industry structure in different provinces.