曼昆经济学原理观部分第6章.pptVIP

Supply, Demand, and Government Policies In a free, unregulated market system, market forces establish equilibrium prices and exchange quantities. While equilibrium conditions may be efficient, it may be true that not everyone is satisfied. One of the roles of economists is to use their theories to assist in the development of policies. 供给、需求与政府政策 在一个自由、无管制的市场系统中，市场力量实现均衡价格和均衡交易量。 这种均衡结果也许是有效的，但并不是每个人对此都感到满意。 经济学家的作用之一就是利用他们的理论帮助制定政策。 Controls on Price... 价格控制… Are usually enacted when policymakers believe the market price is unfair to buyers or sellers. 当政策制定者认为市场价格对买者或卖者不公平时，往往实行价格控制。 Result in government-created price ceilings and floors. 这就促使政府实行价格上限和价格下限政策。 Controls on Price... 价格控制… Price Ceiling 价格上限 A legally established maximum price at which a good can be sold. 可以出售一种物品的法定最高价格。 Price Floor 价格下限 A legally established minimum price at which a good can be sold. 可以出售一种物品的法定最低价格。 How Price Ceilings Affect Market Outcomes Two outcomes are possible when the government imposes a price ceiling: The price ceiling is not binding if set above the equilibrium price. The price ceiling is binding if set below the equilibrium price, leading to a shortage. 价格上限如何影响市场结果 当政府实行价格上限时，可能出现两种价格： ? 如果价格上限高于均衡 价格，价格上限没有限制作用。 ?如果价格上限低于均衡 价格，价格上限对市场有限制作用。 A Price Ceiling That Is Not Binding... 没有限制作用的价格上限... A Price Ceiling That Is Binding... 有限制作用的价格上限... How Price Ceilings Affect Market Outcomes Effects of Price Ceilings A binding price ceiling creates ... shortages because QD QS. Example: Gasoline shortage of the 1970s nonprice rationing Examples: Long lines, Discrimination by sellers 价格上限如何影响市场结果 价格上限的作用 有限制作用的价格上限造成... 短缺，因为 QD QS. 例子: 70年代的汽油短缺 非市场价格方式配给 例子: 排长队, 卖者歧视 Lines at the Gas Pump 加油站前的长队 The Price Ceiling on Gasoline Is Not Binding... 汽油的价格上限没有限制性… The Price Ceiling on Gasoline Is Binding... 汽油的价格上限有限制性... Rent Control in the Short Run and Long Run Rent controls are ceilings placed on the rents that landlords may