地区间贸易流量的产业—空间模型构建与应用

Sector-Specific Spatial Statistic Model for EstimatingInter-regional Trade Flows:A Case Study of Agricultural,Chemical and Electronic Sectors in China

通过深入剖析区域间经济联系的经济地理学理论基础,考虑到同业影响因子,重新构建引力模型,并引入空间滞后因子,利用地理加权回归方法建立了估算区域间贸易流量的产业—空间统计模型,并在中国30个省区投入产出表的基础上,以省区间农业、化工、通信电子3个产业贸易流量的估算为例对上述方法进行了说明。结果表明:①空间统计模型的应用可以显著提高区域间贸易流量的估算可靠性;②随着空间权函数中带宽的缩小,贸易流量显得更加集中。因此,带宽在一定程度上反映了地理活动的空间集聚程度,不同行业应选取不同带宽;③不同行业有不同的同业影响机制和贸易特征,农业输出地以中部地区为主,目的地以沿海地区为主,具有一定的同业竞争关系,而化工、通信行业的产业流动主要发生在东部地区内部,具有很强的同业合作关系。

Based on theories of regional interactions and competition and the gravity model, this paper first develops a sector-specific spatial statistic model to estimate inter-regional trade flows by employing a geographically weighted regression technique. The model takes into consideration sector-specific input-output relationships. That is, in some sectors there exists strong competition between regions while other sectors may need close inter-regional cooperation in terms of supply linkages. The former case results in less inter-regional trade but the latter witnesses more trade. The model also introduces the spatial lag factor of trade flows between regions. Then, the paper applies the model to estimate inter-provincial trade flows of three sample sectors, i.e., agriculture, chemistry and electronics, with data from the 2007 provincial input-output tables of China. The computing result shows that the sector-specific model can significantly increase the reliability of inter-regional trade flow estimation. It also reveals that the bandwidth of weighting function is a key factor in the sector-specific model; that is, the smaller the bandwidth, the more the trade flows. To a certain degree, the bandwidth reflects the degree of geographical concentration of economic activities while the bandwidth itself is different from sector to sector. Different sectors display different features of inter-regional trade flows. For example, agricultural trade flows are mainly from the inland provinces to the coastal ones and show strong intra-sector competition while trade flows of chemical and electronic sectors take place mainly inside the coastal regions and show an intra-sector cooperation relationship.