The correct option for the question "Which of the following factors would most likely cause a decrease in the demand for a normal good?" is: B. A decrease in the price of a substitute good. Detailed Explanation: To understand why option B is the correct answer, we need to first clarify what a normal good is and how demand works in economics. Normal Goods: - Normal goods are those for which demand increases when consumer income rises and decreases when consumer income falls. They are typically goods that people buy more of as they have more money to spend. Demand and Its Determinants: Demand for a good is influenced by several factors, including: 1. Consumer income 2. Prices of related goods (substitutes and complements) 3. Consumer preferences and tastes 4. Population and demographics 5. Expectations about future prices Now, let’s analyze each option: Option A: An increase in consumer income

• Why it’s incorrect: For normal goods, an increase in consumer income typically leads to an increase in demand. If consumers have more income, they are likely to buy more of the normal good, not less. Therefore, this option does not lead to a decrease in demand.

Option B: A decrease in the price of a substitute good

• Why it’s correct: A substitute good is a product that can be used in place of another. For example, if the price of tea (a substitute for coffee) decreases, consumers may choose to buy more tea instead of coffee. This shift in preference would lead to a decrease in the demand for coffee, which is the normal good in this scenario. When the price of a substitute falls, consumers will switch to the cheaper option, thus reducing the demand for the original good.

Option C: A successful advertising campaign for the good

• Why it’s incorrect: A successful advertising campaign typically increases consumer awareness and interest in a product, which usually leads to an increase in demand. Therefore, this option would not cause a decrease in demand for the normal good.

Option D: An increase in the population of consumers

• Why it’s incorrect: An increase in the population generally leads to an increase in demand for goods, including normal goods. More consumers in the market mean more potential buyers, which typically increases demand rather than decreases it.

Summary of Key Points:

1. Normal goods see increased demand with rising consumer income and decreased demand with falling income.
2. Substitutes: A decrease in the price of a substitute good leads consumers to switch their preferences, decreasing demand for the original good.
3. Advertising and population growth generally increase demand, not decrease it.

Revision Summary:

• Normal goods have demand that increases with income and decreases with lower income.
• A decrease in the price of a substitute good leads to a decrease in demand for the original good.
• Successful advertising campaigns and population increases typically boost demand.
• Understanding the relationships between goods (substitutes and complements) is crucial for analyzing demand changes.