Competition and transmission evolution of global food trade: A case study of wheat

Food trade plays an important role in improving each country's food security, and will be even more critical under climate change. Previous literature mainly analyzed the evolution of global food trade from the view of importers with less attention to the possible competitive relationships among importers. In this paper, we explored global food trade from the perspective of competition and investigated regions and countries' adaptive behaviors to enhancing food security in relation to weather patterns, which is relevant to climate change. We collected global wheat trade data from the UN Comtrade database and constructed wheat-trading competition networks. We studied overall features, core-periphery structure (differentiating the whole network into two groups: the core and the periphery) and the evolution of the network over time. The results revealed that wheat trade had formed a global competition pattern, while the number and tightness of competitive relationships gradually decreased with time. A second finding was that core countries and periphery countries were clearly identified in the wheat competition network. Large wheat importers such as Italy, Egypt, Japan and Algeria, were the main driving force for evolution of the competition pattern and played important roles in transferring wheat-trading competition. Finally, a targeted policy framework was put forward to promote the stability and healthy wheat-trading environment.