The double role of GDP in shaping the structure of the International Trade Network

The International Trade Network (ITN) is the network formed by trade relationships betweenworld countries. The complex structure of the ITN impacts important economic processes such asglobalization, competitiveness, and the propagation of instabilities. Modeling the structure of theITN in terms of simple macroeconomic quantities is therefore of paramount importance. Whiletraditional macroeconomics has mainly used the Gravity Model to characterize the magnitude oftrade volumes, modern network theory has predominantly focused on modeling the topology of theITN. Combining these two complementary approaches is still an open problem. Here we reviewthese approaches and emphasize the double role played by GDP in empirically determining boththe existence and the volume of trade linkages. Moreover, we discuss a unified model that exploitsthese patterns and uses only the GDP as the relevant macroeconomic factor for reproducing boththe topology and the link weights of the ITN.