Their results show regional stocks to be more efficient than the sum of national stocks without co-operation. Among developing country regions, more than half of Asia’s agricultural exports go to other Asian countries, but the intra-regional shares drop to 17% in South and Central America and 20% in Africa (WTO, International Trade Statistics for 2011). However, food trade is largely informal in a number of regions, which means that the importance of regional trade may be significantly underestimated.