7. Why do price floors and price ceilings both reduce the quantity of goods traded in those markets?
Answer: When a price floor is imposed above the equilibrium price, the quantity
demanded by buyers falls. Sellers cannot sell what buyers are unwilling to purchase at this price.
8. Why do 10 a.m. classes fill up before 8 a.m. classes during class registration? Use supply and demand
curves to help explain your answer.
Answer: Even though the tuition “price” is the same in both cases, student demand for 10
a.m. classes is typically greater than for 8 a.m. classes. College students often prefer to sleep in
later than punctual attendance at an 8 a.m. class would allow. A shortage of 10 a.m. class space
9. What would happen to the equilibrium price and quantity exchanged in the following cases?
a. an increase in income and a decreasing price of a complement, for a normal good
b. a technological advance and lower input prices
c. an increase in the price of a substitute and an increase in income, for an inferior good
d. s will soon fall, and increasingly costly government
regulations
Answers:
a) Demand would increase, since both changes increase demand. As a result, the price and
quantity exchanged would both increase.