全球粮食贸易网络演变及其驱动因素解析

论文基于全球238个国家和地区的面板数据,研究1988—2018年全球粮食贸易网络的空间格局演变,并引入零膨胀负二项回归构建粮食贸易的引力模型以解析其影响因素,以期揭示全球粮食贸易的驱动因素。结果表明：① 全球粮食贸易规模在波动中呈快速上升态势,贸易增速年际波动较大;贸易商品结构不断多元化,但仍以小麦、玉米和大麦为主。② 全球粮食贸易网络密度不断增强,局部核心节点存在极化现象,但整体贸易网络多元化趋势不断增强。在国家尺度,粮食贸易网络结构由“东西轴线”转向“多点放射”,逐渐从极化转向多元;其中,粮食出口网络核心节点不断增加,但区域粮食出口网络仍受几个核心国家主导;进口网络的集中特征逐渐弱化且更加均衡。③ 土地资源禀赋、农业产业结构、对外开放程度是各个国家和地区参与全球粮食贸易的核心驱动因素,价格差异水平、语言邻近性、空间物理距离、社会治理水平对各个国家和地区参与全球粮食贸易有一定影响,其他因素的影响作用较小。该研究能丰富贸易地理相关研究,提升对全球粮食贸易的科学认知,并为保障中国粮食安全提供支撑。

Change of the global grain trade network and its driving factors

Based on the panel data of 238 countries and regions, this study examined the change of the spatial pattern of the global grain trade network at different scales from 1988 to 2018. The zero-inflated negative binomial was introduced to construct the gravity model for analyzing the driving factors of the global grain trade network. The results show that: 1) The scale of the global grain trade showed a rapid fluctuating rising trend, while the growth rate of trade fluctuated greatly between years. The structure of trade commodities was constantly diversified but is still dominated by wheat, corn, and barley. 2) The density of the global grain trade network is increasing, with polarization of some core nodes and increasing diversification of the overall trade network. For example, the position of North America, Western Europe, East Asia, and so on, in the grain trade network is relatively declining, while the position of Eastern Europe, South America, and so on, has increased. On the national scale, the interaction of grain trade among countries and regions has enhanced, as the structure of the grain trade network has changed from an "east-west axis" to "multi-point radiation" with a gradual shift from polarization to pluralism. Although the number of core nodes in the grain export network is increasing, regional grain export networks are still dominated by only several key countries and show a strong local polarization phenomenon, while the centralized characteristics of import networks are gradually weakened and more balanced. 3) Natural endowment of land resources, the structure of agriculture, and the degree of opening up to the outside world are the core driving factors for countries and regions to participate in the global grain trade network. The levels of price differences, language proximity, spatial distance, and societal governance also have a certain impact on the participation of countries and regions in the global grain trade network. The influence of other factors is relatively small.