2008/16 LEM Working Paper Series

The World-Trade Web: Topological Properties, Dynamics, and Evolution

Giorgio Fagiolo, Javier Reyes, Stefano Schiavo
Weighted Networks; World Trade Web; Distribution Dynamics; Power Laws; Econophysics

  JEL Classifications
F10, D85

This paper studies the statistical properties of the web of import-export relationships among world countries using a weighted-network approach. We analyze how the distributions of the most important network statistics measuring connectivity, assortativity, clustering and centrality have co-evolved over time. We show that all node-statistic distributions and their correlation structure have remained surprisingly stable in the last 20 years -- and are likely to do so in the future. Conversely, the distribution of (positive) link weights is slowly moving from a log-normal density towards a power law. We also characterize the autoregressive properties of network-statistics dynamics. We find that network-statistics growth rates are well-proxied by fat-tailed densities like the Laplace or the asymmetric exponential-power. Finally, we find that all our results are reasonably robust to a few alternative, economically-meaningful, weighting schemes.

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