Which goods have a positive cross-price elasticity?

Shortage goods refer to items that are in limited supply, leading to a situation where demand exceeds supply at a given price. These goods do not inherently show a relationship with other goods in terms of cross-price elasticity. Instead, their market behavior is driven by supply constraints rather than the price dynamics of related products.

Complement goods are items that are consumed together, such as coffee and sugar. When the price of one complement rises, the demand for the other usually decreases, leading to a negative cross-price elasticity. This inverse relationship indicates that these goods are interdependent, unlike substitutes, which exhibit a positive correlation.

Normal goods are those whose demand increases as consumer income rises. While they exhibit a direct relationship with income changes, their cross-price elasticity can vary widely depending on whether they are substitutes or complements to other goods. Therefore, normal goods do not consistently reflect a positive cross-price elasticity on their own.