Which concept refers to a complementary good's effect on consumption?

The concept that best captures the relationship of a complementary good's effect on consumption is known as consumption complementarity. When two goods are complements, an increase in the consumption of one good typically leads to an increase in the consumption of the other. For example, if the price of coffee decreases and consumers buy more coffee, they are likely to purchase more cream as well because these goods enhance each other's utility when consumed together.

In the context of this question, while positive correlation may seem related, it does not specifically address the interaction between complementary goods in the way that consumption complementarity does. Positive correlation generally refers to the relationship where two variables move in the same direction without emphasizing the direct interaction that occurs with complementary goods.

Consumption complementarity effectively highlights that the consumption behavior of one good is dependent on the consumption of another, reflecting the nuanced relationship that characterizes complementary goods.