Which term defines goods that are commonly used together, where the price increase of one leads to decreased demand for the other?

The term that defines goods that are commonly used together is known as complements. When two goods are complements, an increase in the price of one good typically leads to a decrease in the demand for the other. This occurs because consumers often purchase these goods in conjunction; for example, if the price of printers rises, the demand for ink cartridges may decline since consumers are less likely to buy a printer and therefore need fewer ink cartridges.

In contrast, substitutes are goods that can be used in place of each other. If the price of one substitute rises, consumers might switch to the other as a cheaper alternative, leading to increased demand for that substitute. Equilibriums refer to a state in the market where supply equals demand, and variates generally refer to variations or differences, which do not specifically relate to the relationship between goods in terms of demand. Understanding the concept of complementary goods is essential in analyzing consumer behavior and market dynamics.