One might argue that this example concerns only the value of trade, and that in recent decades, the growth of trade by volume also has exceeded that of real GDP growth. But commodity prices affect trade volumes as well, because higher commodity prices force industrial countries to increase the volume of their exports (ten cars instead of five, in the example provided), in order to cover the costs of the same volume of raw material imports.
Because food, fuels, and raw materials comprise about a quarter of global trade, when their prices fluctuate – especially as strongly as they have in recent decades – aggregate trade figures are obviously affected. Given the massive drop in commodity prices lately, there is little need to seek any other explanation for the recent slowdown in trade.