The price elasticity of supply (PES or Es) is a measure used in economics to show the responsiveness, or elasticity, of the quantity supplied of a good or service to a change in its price. The elasticity is represented in numerical form, and is defined as the percentage change in the quantity supplied divided by the percentage change in price. The quantity of goods supplied can, in the short term, be different from the amount produced, as manufacturers will have stocks which they can build up or run down.