ePack: Principles of Microeconomics 6th Edition by Gregory Mankiw

تمرين 5

The equilibrium price of coffee mugs rose sharply last month, but the equilibrium quantity was the same as ever. Three people tried to explain the situation. Which explanations could be right? Explain your logic.
Billy : Demand increased, but supply was totally inelastic.
Marian : Supply increased, but so did demand.
Valerie : Supply decreased, but demand was totally inelastic.