A shift of the demand curve leftward from its original position indicate

1. Analyze the question The question asks what a leftward shift of the whole demand curve means. The key word is shift, which is different from a movement along the curve.

2. Explain the concept

• Movement along the demand curve is caused only by a change in the item's own price. • Price falls: expansion (an increase in quantity demanded). • Price rises: contraction (a decrease in quantity demanded).
• Shift of the demand curve is caused by a change in non-price factors such as income, tastes, the prices of substitutes or complements, population, and expectations. • Rightward shift: an increase in demand. • Leftward shift: a decrease in demand, also called a fall in demand.

3. Solution A leftward shift means that at every price, consumers now buy less than before. This is a fall (decrease) in demand.

Checking the options:

• A. Increase in quantity demanded is a movement down the curve, not a shift. Wrong.
• B. Decrease in quantity demanded is a movement up the curve because of a price rise. Wrong.
• C. Expansion of demand is also a movement along the curve. Wrong.
• D. A fall in demand matches a leftward shift of the whole curve. Correct.
• E. Price effect on demand is a price change, which causes movement along the curve rather than a shift. Wrong.

4. Answer The correct option is D, a fall in demand.

5. Exam tip Remember: "Quantity" words (expansion, contraction, increase or decrease in quantity demanded) = movement along the curve, caused by price. "Demand" words (increase or decrease in demand) = shift of the curve, caused by non-price factors. Also, left = less and right = more.