After five years watching the cycles of feast and famine in West Africa, Margie Morard had some clearly formed ideas about what drives food prices in her part of the world. War, floods, droughts — these are the things that used to determine the cost of bread in Freetown or Timbuktu, says the representative for British Oxfam, who monitors food security in 10 countries lying southwest of the Sahara Desert. That and myopia. In sub-Saharan Africa, boom harvests tend to result in cash-hungry farmers flooding street markets with cheap corn and rice, while lean years see brokers ruthlessly hoard grain in anticipation of a big payday. The extremes can produce heartbreaking scenes of deprivation, says Morard; widespread begging, gaunt children with distended stomachs, families on the move in search of food. But at least they tend to be predictable.