In economic terms, if a small change in price produces a large change in demand, demand is said to be elastic. The oil supply is becoming less elastic as new oil supplies come increasingly from unconventional oil. Elasticity is the term economists use to describe how much supply or demand responds to changes in price. Price elasticity of demand (PED or E d) is a measure used in economics to show the responsiveness, or elasticity, of the quantity demanded of a good or service to increase in its price when nothing but the price changes. More precisely, it gives the percentage change in quantity demanded in response to a one percent change in price.