Their simulation results show that the overall world price impact of trade policy distortions is most significant for rice, at 24%, followed by wheat (14%) and barley (9%). Poorer food-deficit countries and regions, with limited power to manipulate their trade policies, experienced higher price increases than those major trading countries which adopted policy interventions. The authors show that developing countries which are net importers but did not implement trade policy interventions experienced significant welfare losses resulting from interventions implemented by other major trading countries. The lower prices penalise farmers, reducing the incentives for investments that can increase long-term supply.