When we talk about complementary goods, we are talking about those who need another good to be able to be consumed and satisfy, in this way, the consumer's need.
Let's think about a simple example: cocoa powder. The most common is that in order to consume it, you have to use milk or another ingredient if you are going to make a recipe. Well, milk or the other ingredients in which it can be used will be complementary goods, since they need it to be able to be consumed.
However, this concept must be treated with delicacy, since, following the previous example, a person may like to consume cocoa powder without the need for another good, so they would no longer have complementary goods.
Characteristics of complementary goods
Regarding the characteristics of complementary goods, we can highlight the following:
- The complementary goods have a demand related: when a good is bought, it is expected that it will also buy the other good that is a necessary complement
- If the price of a good increases, the demand for the complementary good falls (negative cross elasticity of demand)
- They are goods that complement a single need of a person, but this requires more than one good
We can also talk about the degree of complementarity of the goods, in which it tells us how much complementary one good is with respect to another. Against this, we highlight the following degrees:
- Perfect complements: it is consumed in fixed proportions, if one is consumed, the same amount of another should be consumed
- Normal complements: they are consumed in the same proportions, but there does not have to be an exact relationship of quantities, as in the previous one