世界油料贸易网络演化特征及其影响因素

基于UN Comtrade公布的2011—2020年国际油料贸易数据，采用复杂网络分析法，研究世界油料贸易网络的演化特征，并通过QAP模型探究油料贸易网络的影响因素。结果表明：1）油料贸易网络具有良好的连通性和小世界属性，但整体网络密度及互惠系数相对较低，网络中各节点间的联系有待加强；国际油料出口市场高度集中，进口市场相对分散，贸易重心向以巴西为首的发展中经济体偏移；油料贸易网络存在核心―半边缘―边缘的圈层结构，核心成员国家主要集中在北美和南美地区，美国、巴西和阿根廷是主要的核心国家，对其他国家存在较强的影响力。2）经济规模差异、人均收入差异、人均耕地面积差异和陆地接壤对油料贸易具有显著的正向影响；制度距离和劳动力数量差异则存在显著的负向影响；地理距离在无权网络中与油料贸易负相关，而在加权网络中为正相关。中国虽是油料进口大国和消费大国，但油料进口来源过度集中，进口潜在风险较大。中国应调整油料进口国别结构，构建油料供应网络，深化贸易合作与利益融合，保障油料进口安全。

Evolution Characteristics and Influence Factor of World Oil-Bearing Crops Trade Network

Based on the data on international oil-bearing crop trade published by UN Comtrade from 2011 to 2020, this study adopted the complex network analysis method to investigate the evolution characteristics of the world oil crop trade network and explored the influence factor of the oil crop trade network through the Quadratic Assignment Procedure model. The results indicate that the oil trade network has good connectivity and small world attributes, but the overall network density and reciprocity coefficient are relatively low, and the links between the nodes in the network need to be strengthened. The international oil crop export market is highly concentrated, and the import market is relatively scattered. Brazil's oil crop exports have gradually increased, eroding the market share of the United States and shifting the trade focus to developing economies led by Brazil. The oil crop trade network has a "core- marginal" circle structure. The United States, Brazil, and Argentina are the main core countries, displaying a "tripartite" trend in oil crop trade and having a strong influence on other countries. Economic scale difference, difference in per capita income, per capita cultivated land area difference, and land bordering have a significant positive impact, and institutional distance has a significant negative impact on the unauthorized network and weighted trade network of oil crop trade. There is a negative correlation between the difference in the labor force and the growth of trade volume, and the degree of impact is gradually weakened. Geographical distance has an opposite effect on oil crop trade relations and trade flows. It is negatively correlated with the oil crop trade in the unauthorized network, but positively correlated with the weighted network. China is a major importer and consumer of oil crops, and the import trade has developed rapidly. However, the import sources are excessively concentrated, the import potential risk is large, the position in the trade network is not high, the closeness and betweenness centrality indicators rank low, and its influence on the international oil market does not match its position as a major trading country. In this regard, China should adjust the country structure of oil crop imports, build a supply network, deepen trade cooperation and interest convergence, and ensure the safety of oil crop imports.