3-2 Shifts in Demand Curves

Change in Quantity Demand

A movement between points along on a demand curve

Normal good

Any good for which there is a Direct relationship between changes in income and its demand curve.

Inferior good

Any good for which there is an Inverse relationship between changes in income and its demand curve.

Substitute

Goods that compete for consumer purchases.

Complement

Goods that consumers purchase together with another good.

Change in Demand

and increase (rightward shift) or a decrease (leftward shift) in the demand curve.