The uncertainty in world market prices is transmitted from domestic markets via trade flows, and is determined by shocks to demand and supply, especially in important trading countries, and changing relative prices between domestic and world markets. Macroeconomic uncertainty has a greater effect on world market prices than yield uncertainty. Uncertainty in oilseeds yield has a direct effect on the quantities available for crushing, while macroeconomic uncertainty affects both demand and supply. Vegetable oil demand is closely linked to biodiesel production, which is less strongly affected by macroeconomic uncertainty since consumption is often dictated by mandates.