The income elasticity of demand 10) measures the responsiveness of income to changes in quantity demanded. measures the change in income necessary for a given change in quantity dem is the ratio of the percentage change in income to the percentage change in q measures the responsiveness of quantity demanded to changes in income. 1) When there are more substitutes for a product, the for the product is income elasticity; greater B) income elasticity; smaller ) demand; more price elastic D) demand; less price elastic 12) The more time that elapses, the 12) A) more price elastic is the demand for the product. B) greater the income elasticity of demand for a product