In microeconomics, what is the key difference between a change in demand and a change in quantity demanded?

• A. A change in demand is a movement along the demand curve caused by a change in the good’s own price, while a change in quantity demanded is a shift of the entire demand curve caused by a non-price determinant.
• B. A change in demand refers only to changes in consumers’ income, while a change in quantity demanded refers only to changes in the prices of substitutes and complements.
• C. A change in demand and a change in quantity demanded both describe the same movement along a fixed demand curve when the good’s price changes.
• D. A change in demand is a shift of the entire demand curve caused by a non-price determinant, while a change in quantity demanded is a movement along the demand curve caused by a change in the good’s own price.

Answer: (D)

Verified step by step guidance

1. Understand that the demand curve represents the relationship between the price of a good and the quantity demanded, holding all other factors constant.
2. Recognize that a change in quantity demanded refers to a movement along the same demand curve, which happens when the price of the good itself changes. This means the quantity consumers want to buy changes because the price changed, but the demand curve does not shift.
3. Identify that a change in demand means the entire demand curve shifts either to the right (increase in demand) or to the left (decrease in demand). This shift is caused by changes in non-price determinants such as consumer income, tastes, prices of related goods (substitutes or complements), expectations, or the number of buyers.
4. Distinguish between these two concepts by noting that a movement along the curve (change in quantity demanded) is triggered by price changes of the good itself, while a shift of the curve (change in demand) is triggered by changes in other factors affecting demand.
5. Summarize the key difference: a change in quantity demanded is a movement along the demand curve due to a price change of the good, whereas a change in demand is a shift of the entire demand curve caused by changes in non-price determinants.