In several countries the price on certain commodities is held down by the state, 'artificially' so to speak.Tiberius Decimus Maximus said:Why should food be free? Is it not the most fundamental component, and indeed the very mother, of any economy?
For example in Egypt there's 'subsidized bread' that's always cheap.
http://www.nytimes.com/2008/01/17/world/africa/17bread.html
And let's not forget the famine of 2006 when it was made possible to speculate on the price of corn and similar goods.