In economics, unit elastic (or unitary elastic) refers to a situation in which a change in the price of a good results in an exactly proportional change in the quantity demanded. This means that the percentage change in quantity demanded is exactly the same as the percentage change in price. The demand elasticity of a good with unit elastic demand is 1, indicating a perfectly proportional response to price changes
. It is a fundamental concept used to assess the demand or supply of a good in response to changes in price
