How does cross-price elasticity help in understanding consumer behavior between two substitute goods? If the price of Good A increases, what would you expect to happen to the quantity demanded for Good B?

Cross-price elasticity measures how the quantity demanded of one good changes when the price of another good changes. When two goods are substitutes, like butter and margarine, an increase in the price of Good A (say, butter) usually leads to an increase in the quantity demanded for Good B (margarine). This happens because consumers will look for a cheaper alternative when the price of their preferred choice rises. For example, if the price of butter goes up, people might buy more margarine instead, leading to higher sales for margarine. Thus, cross-price elasticity helps us understand how consumers switch between substitute goods based on price changes.