GIFFEN GOOD: A rare type of good seldom seen in the real world, in which a change in price causes quantity demanded to change in the same direction (in violation of the law of demand). In other words, an increase in the price of a Giffen good results in an increase in the quantity demanded. The existence of a Giffen good requires the existence of special circumstances. First, the good must be an inferior good. Second, the income effect triggered by a change in price must overwhelm the substitution effect. A Giffen good is most likely to result when the good is a significant share of the consumer's budget. See also | law of demand | income effect | substitution effect | inferior good | demand price | quantity demanded | normal good | luxury good | budget |
