"There is a venerable and much-loved concept in micro-economics of the income **elasticity of demand** (‘IED’). **It is a measure of how demand for a good (or service) changes in relation to change in the income of customers**. It is defined as the percentage change in demand divided by the percentage change in income." ([Location 1530](https://readwise.io/to_kindle?action=open&asin=B00BU0NELQ&location=1530)) --- **Tags** -- [[quotes]], [[supply-and-demand]], [[elasticity]] **Source** -- [[20250317012611 - B - Key Strategy Tools]]