Substitution Effect
The tendency for consumers to replace more expensive goods with cheaper alternatives when relative prices change.
What is Substitution Effect?
The substitution effect occurs when a rise in the price of one good causes consumers to buy more of a relatively cheaper substitute, holding real income constant. It is one of two components — alongside the income effect — that explain why demand curves slope downward. When gasoline prices rise, for example, consumers may shift toward public transportation or more fuel-efficient vehicles. The substitution effect is always negative: as the price of a good rises, quantity demanded falls as consumers seek alternatives, regardless of income level.
Example
When the price of beef rose sharply in 2021–2022 due to supply chain disruptions and higher feed costs, US consumers shifted purchases toward chicken and pork. The USDA reported a measurable decline in per-capita beef consumption alongside rising poultry demand, illustrating the substitution effect in consumer markets.