Price elasticity of supply measures the responsiveness of the quantity supplied of a good to a change in its price. It is calculated as the percentage change in quantity supplied divided by the percentage change in price. If the price elasticity of supply is greater than 1, supply is elastic. If it is less than 1, supply is inelastic. If it is equal to 1, supply is unitary elastic. Examples of perfectly elastic and perfectly inelastic supply curves are also provided. Factors like time, production capacity, producers, and stored products can affect the price elasticity of supply. An example problem calculates the price elasticity of supply for an individual supplying bags and finds it to be elastic at 4.