In economics, an inferior good is a good whose demand decreases when consumer income rises (or demand increases when consumer income decreases), unlike normal goods, for which the opposite is observed. Normal goods are those goods for which the demand rises as consumer income rises.

Inferiority, in this sense, is an observable fact relating to affordability rather than a statement about the quality of the good. As a rule, these goods are affordable and adequately fulfill their purpose, but as more costly substitutes that offer more pleasure (or at least variety) become available, the use of the inferior goods diminishes. Direct relations can thus be drawn from inferior goods to socio-economic class. Those with constricted incomes tend to prefer inferior goods for the reason of the aforementioned observable inferiority.

Depending on consumer or market indifference curves, the amount of a good bought can either increase, decrease, or stay the same when income increases.