Learning Contents:                                                              ·              Extension of Demand ·              Contraction of Demand    Introduction As the Law of Demand states, other things remaining constant, when the price of a commodity falls, consumers buy more of it; if the price of a commodity rises, they buy less of it. Therefore, the price may either go up or down and this cause the consumer to purchase less or more of a commodity respectively. Movements along the demand curve means moving ‘up or down’ the demand curve. When Price becomes the only reason for a change in the demand for a commodity, it is called the movements along the demand curve. Such movements along the demand curve are known as an  extension of demand (downward movement ) and contraction of demand ( upward movement).   A movement along the demand curve is also known as a  change in the quantity demand for a commodity. The change in quantity demand is classified into two