A good is said to be inferior if its demand falls as its price rises. This means that as the price of the inferior good increases, consumers tend to switch to alternative goods, resulting in a decrease in demand for the inferior good. This is different from a normal good, where demand increases as income increases, resulting in an increase in demand as the price of the good increases. In the case of an inferior good, as consumers' income increases, they are likely to switch to superior alternatives, causing the demand for the inferior good to decrease.