Complementary Goods:Complementary goods are products that are used together, and the demand for one good increases the demand for the other.
Elasticity of Demand: The measure of how responsive the quantity demanded of a good is to a change in its price, with the presence of substitute goods being a key determinant of demand elasticity.
Cross-Price Elasticity of Demand:The measure of how the quantity demanded of one good changes in response to a change in the price of another good, which is used to identify substitute and complementary goods.