# Demand Elasticity Inelasticity and elasticity of demand refer to the degree to which demand responds to a change in another economic factor, such as price, income level, or substitute availability. [Elasticity](https://www.investopedia.com/terms/e/elasticity.asp) measures how demand shifts when other economic factors change. When fluctuating demand is unrelated to an economic factor, it is called inelasticity. Price is the [most common economic factor](https://www.investopedia.com/ask/answers/012915/what-effect-price-inelasticity-demand.asp) used when determining elasticity or inelasticity. Other factors include income level and substitute availability. --- Date: 20220606 Links to: Tags: #review References: * [Elasticity vs. Inelasticity of Demand: What's the Difference?](https://www.investopedia.com/ask/answers/012915/what-difference-between-inelasticity-and-elasticity-demand.asp)