Changing Patterns of Global Agri-Food Trade and the Economic Efficiency of Virtual Water Flows

International agri-food trade has expanded rapidly during the past decades and changed considerably in structure with important implications, especially for developing economies. One of the main environmental concerns regarding international trade is the exploitation and redistribution of water resources. In this paper, we use the virtual water approach for analyzing the relationship between global agri-food trade, its structure and virtual water flows in the period of 1986-2011. Specifically, for five regions and the world, we calculate growth rates of interregional trade values and virtual water volumes, the contribution of different product groups to trade and the economic water efficiency of imports and exports. Our findings show that, over time, trade values have generally increased more rapidly than virtual water volumes. In Africa and Southern America, virtual water outflows have roughly quadrupled since 1986. In all regions, staples and industrial products account for the largest share in virtual water trade. The recent shift towards high-value exports is beneficial for low-income countries from a regional economic water efficiency perspective due to high trade values and low associated virtual water volumes. Economic water efficiency of trade has increased in all regions since 2000 and the return to virtual water outflows is especially high in Europe.