Which of the following statements is true?
A) The demand curve for a group of consumers in a market is simply the horizontal summation of each individual's demand.
B) The single demand curve shows the quantity of a good that people will buy, allowing all factors (price, income, expected future prices, etc.) to vary.
C) An increase in income will cause a person to move down and to the right along her demand curve.
D) All of the above are true.

Question

Quizplus · Accepted Answer

The demand curve for a group of consumers is the horizontal summation of each individual's demand. The other statements are incorrect because a single demand curve holds other factors constant (ceteris paribus), and an increase in income typically shifts the demand curve rather than causing movement along it.

Which of the Following Statements Is True