An analysis of the dynamic structure and evolution of international rock phosphate trade

The significant increase in global demand for agricultural products and the shift in the global geopolitical balances have underscored the importance of access to reliable fertilizer markets to ensure global food security. In this paper the dynamic structure and evolutionary mechanisms of the global rock phosphate trade network (GRPTN) are explored using time discrete dynamic network models with time-across dependences in the pre-pandemic period 2015–2020. The coefficient estimates reveal the driving forces behind the establishment of trade links in the GRPTN. The main features identified include low density and reciprocity, small world and scale free character, decentralized structure, slight disassortativity, and moderate geographic heterophily. In addition, the results of fitting a Temporal Exponential Random Graph Model (TERGM) confirm the expected effects of the structural variables as well as those of different economic, geographic, and time-dependence covariates, including the Agriculture Value Added and the Cultivated area of the exporting country, the total trade value of both the importing and exporting countries, the specific region to which the importing or exporting country belongs and geographical contiguity. Moreover, the time-dependence effects are significant and indicate a high level of stability of the GRPTN both in terms of the persistence of existing links and in the infrequent appearance of new ties. The results confirm the geostrategic importance of this non-renewable component essential for ensuring adequate yields in agricultural production.