What defines inelastic demand?

Inelastic demand is characterized by a situation where the percentage change in price results in a smaller percentage change in the quantity demanded. This means that when the price of a good or service increases, the amount demanded by consumers does not decrease as significantly in percentage terms. For example, if the price of a necessity such as insulin increases, people who need it will still purchase nearly the same quantity because their need is not very responsive to price changes.

This property of inelastic demand indicates that consumers prioritize the purchase of certain goods even when prices rise, demonstrating a lack of substitutes or the necessity of the good. The concept of inelastic demand is critical in understanding how markets function, particularly for essential goods.

The other options portray different characteristics of demand elasticity that do not accurately describe inelastic demand specifically. For instance, one suggests that demand falls to zero with a price increase, which aligns more with elastic demand, while another implies that the quantity demanded changes in the same proportion as price, characterizing unitary elasticity. The option that refers to demand being unaffected by price suggests a completely inelastic scenario but does not capture the nuanced definition of inelastic demand as understood in economic terms.