Which concept measures the responsiveness of quantity demanded to price changes?

The concept that measures the responsiveness of quantity demanded to price changes is the elasticity of demand. This economic principle quantifies how sensitive consumers are to changes in the price of a good or service. When the price decreases, the elasticity of demand indicates how much the quantity demanded will increase, and vice versa for price increases.

High elasticity suggests that consumers are very responsive to price changes, meaning a small increase in price could lead to a significant drop in the quantity demanded. On the other hand, low elasticity means that price changes have little effect on the quantity demanded. Understanding the elasticity of demand is crucial for businesses and economists because it affects pricing strategies, revenue projections, and overall market behavior.

The other concepts, such as elasticity of supply, marginal cost, and fixed costs, focus on different aspects of economics. Elasticity of supply examines the responsiveness of quantity supplied to price changes, marginal cost relates to the cost of producing one more unit of a good, and fixed costs refer to expenses that do not change with the level of output. Each of these plays a role in economic analysis, but they do not measure how quantity demanded responds to price changes in the way that elasticity of demand does.