In microeconomics, to say a consumer has demand for a good, what must be true?

• A. The consumer must want the good, even if they cannot afford it at current prices.
• B. The consumer must be able to buy the good, even if they have no desire for it.
• C. The consumer must be willing and able to buy the good at a given price over a given time period.
• D. The consumer must have purchased the good at least once in the past.

Answer: (C)

Verified step by step guidance

1. Understand the concept of demand in microeconomics: Demand refers to the quantity of a good or service that a consumer is both willing and able to purchase at various prices over a specific period of time.
2. Recognize that simply wanting a good is not sufficient for demand; the consumer must also have the financial means or ability to purchase it at the given price.
3. Note that being able to buy a good without the desire to do so does not constitute demand, as demand requires both willingness (preference) and ability (purchasing power).
4. Understand that past purchase history is not a necessary condition for current demand; demand is about current willingness and ability to buy, not past behavior.
5. Conclude that the correct definition of demand is: the consumer must be willing and able to buy the good at a given price over a given time period.