In economics, what is the term for a change in quantity demanded caused by a product’s own price change?

In economics, a change in quantity demanded caused by a product’s own price change is called a movement along the demand curve.

A demand curve represents the quantities consumers are willing and able to buy at different prices, with other conditions held constant. When price falls, consumers generally move downward along the curve and buy more; when price rises, they generally move upward and buy less.

A shift is different. The demand curve shifts when a determinant other than the good’s own price changes. Examples include consumer income, tastes, expectations, population, or the prices of related goods. A rise in income might shift demand for a normal good to the right.

Economists also discuss substitution and income effects when explaining why a price change affects purchases. Those effects help explain the movement, but they are not alternative names for the movement itself. Keeping “demand” and “quantity demanded” separate prevents a common graph-reading error.