Price elasticity of supply is the measure of the responsiveness of quantity supplied to a change in price. A product is perfectly elastic when the the quantity supplied is infinite with the 1% change in price. A product is relatively elastic if with 1% change in price there is a more than 1% change in supply. A product is relatively inelastic if with a 1% change in price the change in the supply is less than 1%. A product is unit elastic if after 1% change in the price the change in supply is equal to 1%.