Spanning trees of the World Trade Web: real-world data and the gravity   model of trade
  In this paper, we investigate the statistical features of the weighted international-trade network. By finding the maximum weight spanning trees for this network we make the extraction of the truly relevant connections forming the network's backbone. We discuss the role of large-sized countries (strongest economies) in the tree. Finally, we compare the topological properties of this backbone to the maximum weight spanning trees obtained from the gravity model of trade. We show that the model correctly reproduces the backbone of the real-world economy. 
Patryk Skowron and Mariusz Karpiarz and Agata Fronczak and Piotr   Fronczak
physics.soc-ph q-fin.GN