The responsiveness of demand to a change in income is the measurement of

Income elasticity of demand is the measurement of the responsiveness of demand to a change in income. In other words, it measures how sensitive the quantity demanded of a good is to changes in income. When income increases, some goods may become more affordable and their demand may increase, while for other goods, demand may remain constant or even decrease. The income elasticity of demand helps to understand these changes and is calculated as the percentage change in the quantity demanded of a good divided by the percentage change in income.