Suppose that a decrease in the price of X results in less of good Y sold. What are X and Y called?

Question

Quizplus · Accepted Answer

When a decrease in the price of X results in less of good Y sold, X and Y are called substitute goods. This means that consumers see X and Y as interchangeable, and when the price of X goes down, they switch to buying more of X and less of Y. This is different from complementary goods, which are goods that are typically consumed together (like peanut butter and jelly), and where a decrease in the price of one good would lead to an increase in the consumption of both goods.

Suppose That a Decrease in the Price of X Results