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