International crop trade networks: The impact of shocks and cascades 
Rebekka Burkholz, Frank Schweitzer 

Analyzing available FAO data from 176 countries over 21 years, we observe an increase of complexity in the international trade of maize, rice, soy, and wheat. A larger number of countries play a role as producers or intermediaries, either for trade or food processing. In consequence, we find that the trade networks become more prone to failure cascades caused by exogenous shocks. In our model, countries compensate for demand deficits by imposing export restrictions. To capture these, we construct higher-order trade dependency networks for the different crops and years. These networks reveal hidden dependencies between countries and allow to discuss policy implications.

International trade networks in 2013 for maize (M), rice (R), soy (S), and wheat (W). Each node is colored according to the world map. The color of a link ( i;j ) corresponds to the exporting country i , with a link weight proportional to a logarithmic transformation of the export quantity: log (1 + wij ) . Links with larger weights are plotted on top of smaller ones. Square node shapes indicate that the respective country is a net importer, while circles refer to net exporters. The node size is proportional to a log transformation of their net imports or net exports. The twenty biggest nodes have their ISO-3 country code assigned . Isolated nodes (i.e. without connections) are omitted in a network plot.

https://arxiv.org/pdf/1901.05872.pdf

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