宏观经济学macroeconomics-6.ppt

* 5 5 * 14 11 * 2 * 15 12 * 24 15 * 25 15 * * 29 20 * 30 22 * 31 21 * 31 21 * 30 22 * 39 29 * 41 30 * * * CASE STUDY: Queues at the Petrol Pump Economists blame government regulations that limited the price oil companies could charge for petrol. In 1973, OPEC raised the price of crude oil in world markets. Crude oil is the major input in petrol, so the higher oil prices reduced the supply of petrol. What was responsible for the long queues? ? 2011 Cengage South-Western Figure 2 The Market for Petrol with a Price Ceiling (a) The Price Ceiling on Petrol Is Not Binding Quantity of Petrol 0 Price of Petrol 1. Initially, the price ceiling is not binding . . . Price ceiling Demand Supply, S1 P1 Q1 ? 2011 Cengage South-Western Figure 2 The Market for Petrol with a Price Ceiling (b) The Price Ceiling on Petrol Is Binding Quantity of Petrol 0 Price of Petrol Demand S1 S2 Price ceiling QS 4. . . . resulting in a shortage. 3. . . . the price ceiling becomes binding . . . 2. . . . but when supply falls . . . P2 QD P1 Q1 ? 2011 Cengage South-Western CASE STUDY: Rent Control in the Short Run and Long Run Rent controls are ceilings placed on the rents that landlords may charge their tenants. The goal of rent control policy is to help the poor by making housing more affordable. One economist called rent control “the best way to destroy a city, other than bombing.” ? 2011 Cengage South-Western Figure 3 Rent Control in the Short Run and in the Long Run (a) Rent Control in the Short Run (supply and demand are inelastic) Quantity of Apartments 0 Supply Controlled rent Rental Price of Apartment Demand Shortage ? 2011 Cengage South-Western Figure 3 Rent Control in the Short Run and in the Long Run (b) Rent Control in the Long Run (supply and demand are elastic) 0 Rental Price of Apartment Quantity of Apartments Demand Supply Controlled rent Shortage ? 2011 Cengage South-Western How Price Floors Affect Market Outcomes When the government imposes a price floor, two outcomes are po