When quantity demanded decreases in response to a change in price, it means there is a movement up along the demand curve. This occurs because the law of demand states that as the price of a good increases, the quantity demanded decreases, and vice versa. Thus, a decrease in quantity demanded due to price change reflects a movement along the same demand curve rather than a shift in the demand curve itself. In contrast, if the demand curve shifts, it indicates a change in demand caused by factors other than price, such as changes in income, consumer preferences, or the prices of related goods.
Explanation:
- A decrease in quantity demanded happens when the price of a good or service rises, and consumers respond by buying less of it.
- This change is illustrated as a movement up along the fixed demand curve, not a shift of the curve.
- A shift of the demand curve represents an overall change in demand at every price, caused by non-price factors.
- Hence, quantity demanded changes due to a price change are movements along the demand curve, not shifts of the curve.
This distinction is important in understanding consumer behavior and market responses to pricing.