RCEP国家谷物贸易网络演化及三元动力机制

THE EVOLUTION OF GRAIN TRADE NETWORKS AND THE TRIPLE-DRIVING MECHANISM IN RCEP

关键词:  谷物贸易  网络演化  TERGM模型  社会网络分析  三元动力机制

Key words:  grain trade  network evolution  TERGM model  social network analysis  triple-driving mechanism

摘要:

目的 揭示RCEP（Regional Comprehensive Economic Partnership，RCEP）国家谷物贸易网络的结构特征和演化趋势，考察驱动谷物贸易网络演化的三元动力机制，从而更好地把握未来国际谷物供应链中的风险与机遇，维护中国谷物市场稳定和粮食安全。方法 文章基于2000—2023年联合国贸易数据库构建RCEP国家谷物贸易网络，运用社会网络分析工具（Social Network Analysis，SNA）量化剖析网络的结构特征和演化趋势，最后通过动态指数随机图模型（Temporal Exponential Random Graph Models，TERGM）探究网络演化的三元动力机制。结果 （1）2000—2023年RCEP国家谷物贸易出口总额呈快速波动增长趋势。中国在RCEP国家的谷物进口额波动增加，进口主要来源于澳大利亚、越南、泰国和缅甸，出口呈下降趋势，主要出口对象是韩国和日本，中国已由谷物净出口国向净进口国转变。（2）网络密度、网络效率、平均聚类系数上升，平均路径长度下降，区域内贸易联系持续加强，贸易效率快速提升。相邻年份网络结构保持较高的相似性，贸易关系在稳定中逐步调整。（3）泰国、越南和澳大利亚等在区域谷物贸易网络中始终保持重要地位，中国在网络中度中心度和接近中心度均处于较高水平，尽管接近中心度、中介中心度从2010年起有所下降，但仍对贸易网络结构有重要影响。随着区域合作加强，老挝、柬埔寨等国的中心性显著提升，而泰国的桥接作用有所减弱，其他成员国的贸易路径逐渐趋于多样化，RCEP区域贸易网络呈现更紧密、更高效的整合趋势。（4）中国、澳大利亚的核心地位逐步巩固，泰国、印度尼西亚等国的影响力有所减弱，而菲律宾、柬埔寨等国家则持续处于边缘地位。国家间贸易联系愈加复杂，东亚与东南亚的贸易界限逐渐模糊。（5）RCEP谷物贸易网络受社会选择、关系嵌入和网络自组织机制共同驱动，社会选择机制奠定了网络的基础结构，驱动网络动态演化，关系嵌入机制增强了网络稳定性和韧性，自组织机制则优化了网络的内部结构，推动网络动态平衡。结论 RCEP国家之间的谷物贸易关系正在朝着复杂性和一体化的方向发展，结果启示：应加强与RCEP国家的贸易合作，强化与核心谷物出口国的贸易联系，同时充分发挥中国在谷物贸易网络中的影响力，积极参与区域谷物贸易规则的制定和完善。此外，要重视三元动力机制在优化贸易网络结构，提升网络韧性和全局效能的作用。

Abstract:

To reveal the structural characteristics and evolutionary trends of the grain trade network among RCEP countries, this study examines the tripartite driving mechanisms underlying the network's evolution. The objective is to better understand risks and opportunities in the future international grain supply chain, ensuring the stability of China's grain market and food security. Based on the data from UN Comtrade Database, this study constructed a RCEP grain trade network from 2000 to 2023 and employed social network analysis (SNA) to quantify and analyze its structural features and evolutionary trends. Furthermore, a dynamic temporal exponential random graph model was applied to explore the tripartite driving mechanisms of network evolution. The results indicated that: (1) From 2000 to 2023, the total export value of cereal trade among RCEP countries exhibited a trend of rapid yet fluctuating growth. China's cereal imports from RCEP members increased with fluctuations, primarily originating from Australia, Vietnam, Thailand, and Myanmar, while its exports—mainly to the republic of Korea and Japan—showed a downward trend. Consequently, China has transitioned from a net exporter to a net importer of cereals. (2) Network density, network efficiency, and the average clustering coefficient increased, while the average path length decreased. These indicators point to a continuous strengthening of intra-regional trade ties and a rapid improvement in trade efficiency. The network structure maintained high similarity between adjacent years, reflecting a pattern of gradual adjustment within an overall stable framework. (3) Thailand, Vietnam, and Australia have consistently maintained pivotal positions within the regional cereal trade network. China’s degree centrality and closeness centrality remained at high levels; although its closeness and betweenness centrality have declined since 2010, it continues to exert a significant influence on the network structure. With the strengthening of regional cooperation, the centrality of countries such as Laos and Cambodia has improved significantly, while Thailand's "bridging" role has weakened. As trade paths for other member states become increasingly diversified, the RCEP regional trade network is trending toward tighter and more efficient integration. (4) The core positions of China and Australia have been gradually consolidated, whereas the influence of countries like Thailand and Indonesia has relatively diminished. In contrast, the Philippines and Cambodia have remained in peripheral positions. Trade links between nations have become increasingly complex, leading to a gradual blurring of the traditional trade boundaries between East Asia and Southeast Asia. (5) The evolution of the RCEP cereal trade network is jointly driven by mechanisms of social selection, relational embeddedness, and network self-organization. Specifically, the social selection mechanism establishes the foundational structure and drives dynamic evolution; the relational embeddedness mechanism enhances network stability and resilience; and the self-organization mechanism optimizes the internal structure to promote a dynamic equilibrium within the network. In summary, grain trade relationships among RCEP countries are evolving toward greater complexity and integration. And China should strengthen trade cooperation with RCEP countries, reinforce its trade connections with major grain exporters, and fully leverage its influence in the grain trade network by actively participating in the formulation and refinement of regional trade rules. Additionally, it is crucial to recognize the role of tripartite driving mechanisms in optimizing the trade network structure, enhancing network resilience, and improving overall efficiency.