Which of the following is NOT a factor that brings about changes in demand?

1. Analyze the question The question asks which option is NOT a factor that causes a change in demand. In economics, "change in demand" means a shift of the whole demand curve, which is different from a "change in quantity demanded."

2. Explain the concept

• Change in quantity demanded is a movement along the demand curve. It is caused only by a change in the price of the good itself.
• Change in demand is a shift of the entire demand curve. It is caused by non-price factors, often called determinants of demand: • Consumer income (real income) • Tastes and preferences • Prices of related goods (substitutes and complements) • Population size and structure • Government policy (taxes, subsidies, regulations) • Expectations about future prices or income

3. Go through the options

• A. The price of the good or service: This only moves us along the existing demand curve (an extension or contraction of demand). It does not shift the curve, so it is not a cause of a change in demand.
• B. A change in real income: More income raises demand for normal goods, so the curve shifts. This is a factor.
• C. Government policy: Taxes, subsidies, and import bans affect how much people can buy or want to buy, so the curve shifts. This is a factor.
• D. Increase in population: More people means more buyers at every price, so the curve shifts right. This is a factor.

4. Answer Options B, C, and D all shift the demand curve. Only A does not, because the price of the good itself causes a change in quantity demanded, not a change in demand.

Correct answer: A

5. Exam tip When you see "change in demand," remember that the good's own price is never the cause. Own price changes mean movement along the curve, and everything else means a shift of the curve. A quick way to remember it: "Price moves along, others shift the curve."