2. The following graph shows the market for pianos in 2011. Between 2011 and 2012, the equilibrium quantity of pianos remained constant, but the equilibrium price of pianos decreased. From this, you can conclude that between 2011 and 2012, the supply of pianos__________(increased or decreased) and the demand for pianos___________(increased or decreased) 3. The market price of pizza in a college town increased recently, and the students in an economics class are debating the cause of the price increase. Some students suggest that the price increased because several pizzerias in the area have recently gone out of business. Other students attribute the increase in the price of pizza to a recent increase in the price of hamburgers at local burger joints. Everyone agrees that the increase in the price of hamburgers was caused by a recent increase in the price of ground beef, which is not generally used in making pizza. Everyone also agrees that pizzerias and burger joints are entirely separate entities—that is, there aren’t places that serve both pizza and hamburgers.