if the price of commodity X rises and consumers shift to commodity Y, then commodity X and Y are?

If the price of commodity X increases and consumers start buying more of commodity Y instead, then commodity X and Y are substitutes. Substitutes are products that can be used in place of each other. When the price of one substitute increases, consumers tend to switch to the other substitute because it becomes relatively cheaper. For example, if the price of beef increases, consumers might switch to chicken instead. On the other hand, complements are products that are typically used together, such as gasoline and cars. If the price of gasoline increases, consumers might reduce their demand for cars as well, since they need gasoline to run their cars. Inferior goods are products that people tend to buy less of as their income increases, such as instant noodles. Finally, bought goods is not a recognized economic term.