Fig. 1
From: Economic shifts in agricultural production and trade due to climate change
Historical evolution of the structure of the global trade network for the period 1870–2014. a We illustrate the historical evolution of the global trade network by using bilateral trade data from the Correlates of War Project Data Set version 4.0 (Barbieri and Keshk, 2016). The bilateral trade dataset (Barbieri and Pollins, 2009) tracks total national trade and bilateral trade flows between states from 1870 to 2014. We developed a metric (S) based on Shannon’s entropy measure, which reflects the structure of the trade network by quantifying the underlying relationship between importing and exporting regions. Small values of the S index represent a centralised network structure, where export/import flows are dominated by few regions, while larger values of S characterise a more decentralised trading structure, where export/import flows are more uniformly distributed between all regions. b–e Network plots characterising the structure of the global trading network from the beginning of the 20th century to the beginning of the 21st century
