Related to the
Economics in Practice on p. 50: The Amazon Kindle and the electronic textbooks available for the Kindle are complementary goods. Electronic textbooks and traditional, hard-copy textbooks are substitute products. If the price of electronic textbooks for the Kindle increases
◦ demand for the Kindle decreases, demand for electronic textbooks decreases, and demand for traditional, hard-copy textbooks increases.
◦ the quantity of Kindles demanded decreases, demand for electronic textbooks decreases, and the quantity of traditional, hard-copy textbooks demanded increases.
◦ demand for the Kindle increases, the quantity of electronic textbooks demanded decreases, and demand for traditional, hard-copy textbooks increases.
◦ demand for the Kindle decreases, the quantity of electronic textbooks demanded decreases, and demand for traditional, hard-copy textbooks increases.