Piccardi Carlo, Tajoli Lucia
Department of Electronics and Information, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jun;85(6 Pt 2):066119. doi: 10.1103/PhysRevE.85.066119. Epub 2012 Jun 18.
The World Trade Web (WTW), which models the international transactions among countries, is a fundamental tool for studying the economics of trade flows, their evolution over time, and their implications for a number of phenomena, including the propagation of economic shocks among countries. In this respect, the possible existence of communities is a key point, because it would imply that countries are organized in groups of preferential partners. In this paper, we use four approaches to analyze communities in the WTW between 1962 and 2008, based, respectively, on modularity optimization, cluster analysis, stability functions, and persistence probabilities. Overall, the four methods agree in finding no evidence of significant partitions. A few weak communities emerge from the analysis, but they do not represent secluded groups of countries, as intercommunity linkages are also strong, supporting the view of a truly globalized trading system.
世界贸易网络（WTW）模拟了国家间的国际交易，是研究贸易流动经济学、其随时间的演变以及对包括国家间经济冲击传播在内的诸多现象的影响的重要工具。在这方面，社区的可能存在是一个关键点，因为这意味着国家是按照优先伙伴群体来组织的。在本文中，我们使用四种方法来分析1962年至2008年期间世界贸易网络中的社区，这四种方法分别基于模块度优化、聚类分析、稳定性函数和持续性概率。总体而言，这四种方法都没有发现明显划分的证据。分析中出现了一些薄弱的社区，但它们并不代表孤立的国家群体，因为社区间的联系也很紧密，这支持了真正全球化贸易体系的观点。
