Buffer stock schemes are a way to control the prices of a commodity. Stockpiles of the commodity are created, so that the market can be flooded to decrease the price if so desired. A price ceiling and floor are used to create a limit of where the price of the commodity can be set. If there is a surplus the government buys up the extra goods, and if there is a shortage the government fills in. Buffer stock schemes are used as a safeguard against market volitility.