What describes a demand curve shift?

• A. A movement of the entire demand curve caused by a change in a non-price determinant: income, tastes, prices of related goods, expectations, or population.
• B. A change in price causing a movement along the demand curve.
• C. A movement along the supply curve.
• D. A shift in the demand curve due to production costs.

Answer: (A)

A demand curve shifts when a non-price determinant changes, causing the entire curve to move left or right. This means that at every price, the quantity demanded is higher or lower depending on the determinant. Income, tastes, prices of related goods, expectations, and population are classic examples of such determinants. This is different from a movement along the curve, which happens when the good’s own price changes and only the quantity demanded changes along the same curve. Production costs affect supply, not demand, so they would shift the supply curve instead of the demand curve.