If the percentage change in the quantity demanded is negative while the percentage change in income is positive,the good is an inferior good.

Question

Quizplus · Accepted Answer

This is because an inferior good is a good for which demand decreases as income increases. So if the percentage change in quantity demanded is negative (decreases) while the percentage change in income is positive (increases), the good is indeed an inferior good.

If the Percentage Change in the Quantity Demanded Is Negative