Oyster crackers are a complement for clam chowder. If the price of clam chowder falls, the quantity of clam chowder demanded falls rises which raises lowers the demand for oyster crackers. Because of the change in the equilibrium quantity of oyster crackers, the demand for wheat flour by oyster crackers producers rises falls , causing the equilibrium price of wheat flour to decrease increase . This means producers of bread face higher lower input prices, and the supply of bread decreases increases . The resulting rise fall in the price of bread causes people to substitute away from cereal and toward bread away from bread and toward cereal , so the demand for cereal rises falls.