AP MicroeconomicsMicroeconomic Theory
Giffen Good
A Giffen good is a rare good whose quantity demanded rises when its price rises, violating the law of demand.
It happens with strongly inferior staple goods when a price increase makes consumers so much poorer in real terms that they buy more of the cheap staple and less of pricier substitutes. The income effect outweighs the substitution effect. Giffen goods are largely theoretical and very rare.