A substitute good is a good that can be used as an alternative or replacement for another good.
E.g. A Coke Zero bought in place of a Pepsi Max.
Complementary goods or services
A complementary good is a good that is often used together with another good.
E.g. An iPhone cover and an iPhone.
Having one will add value to the other.
When deciding whether goods are substitutes or complementary, ask yourself: Could this good be used in place of another good? If yes, it is a substitute good.
TOP TIP
Could this good be used together with another good? If yes, it is a complementary good. It helps to include an example of goods when explaining each term.
Q7 Indicate whether the following items are substitutes for or complementary to a cup of coffee with a ✔ in the correct box.
Substitute Complementary
A cup of tea Milk & sugar A pastry An energy drink e.g. Monster
Q8 (i) Indicate whether the following items are likely to be substitutes for or complementary to a chicken fillet roll purchased in a local deli.
Substitute Complementary
A breakfast roll A bottle of water A sausage roll Crisps
Q8 (ii) Pick one item from part (i) and explain the reason why it is a substitute or complement to a chicken fillet roll (Note: you should explain how the good is either a substitute or complementary good to explain it properly in your reason)