Why substitution effect matters to a first-time founder
The substitution effect helps founders predict where customers may move when relative prices change. A price rise can shift demand towards alternatives even if customers’ income is unchanged. Understanding the nearest substitutes supports pricing, packaging and positioning decisions, especially when competitors or input costs move quickly.
Examples of substitution effect
A café raises the price of oat-milk coffee from £3.50 to £4.20 while dairy coffee stays at £3.50. Some customers switch to dairy because oat coffee is now relatively more expensive. That change illustrates substitution, although observed sales may also reflect preferences, promotions and changes in customers’ purchasing power.
Common misunderstanding
The substitution effect is not the whole response to a price change. Economists separate it from the income effect, which reflects the change in purchasing power caused by the new price. It also does not mean every customer views two products as interchangeable; preferences, switching costs and availability shape actual behaviour.
When to use it
Use the concept when evaluating a price change or identifying the alternatives customers may choose instead. Research real switching behaviour and test willingness to pay rather than assuming the closest-looking product is the substitute. For precise economic analysis, separate substitution from income effects and state the assumptions behind the model.