曼昆宏观经济学武大19章.ppt

1、A Macroeconomic Theory of the Open Economy开放经济的宏观经济理论开放经济的宏观经济理论Chapter 19Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.Open Economies 开放经济开放经济nAn open economy is one that interacts freely with other economies around the world.开放经济是一个与世界其他经济体进行开放经济是一个与世界其他经济体进行自由交易的经济体。自由交易的经济体

2、。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.Key Macroeconomic Variables in an Open EconomyuThe important macroeconomic variables of an open economy include:unet exports unet capital outflowunominal exchange ratesureal exchange rates Harcourt,Inc.items and derived items copyr

3、ight 2001 by Harcourt,Inc.开放经济中关键的宏观经济变量开放经济中关键的宏观经济变量u一个开放经济中重要的宏观经济变一个开放经济中重要的宏观经济变量包括量包括:u净出口净出口 u净资本外流净资本外流u名义汇率名义汇率u实际汇率实际汇率 Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.Basic Assumptions of a Macroeconomic Model of an Open Economy开放经济的宏观经济模型的基本假设开放经济的宏观经济模型的基本假设uThe mode

4、l takes the economys GDP as given.模型把模型把GDP作为既定的。作为既定的。uThe model takes the economys price level as given.模型把经济的物价水平作为既定的。模型把经济的物价水平作为既定的。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.SUPPLY AND DEMAND FOR LOANABLE FUNDS AND FOR FOREIGN-CURRENCY EXCHANGEnThe Market for Loanable

5、 FundsS=I+NCOAt the equilibrium interest rate,the amount that people want to save exactly balances the desired quantities of investment and net capital outflows.Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.可贷资金市场与外汇市场的供给与需求可贷资金市场与外汇市场的供给与需求n可贷资金市场可贷资金市场S=I+NCO在均衡利率时，人们想储蓄的量正好与

6、合在均衡利率时，人们想储蓄的量正好与合意的国内投资和净资本外流量平衡。意的国内投资和净资本外流量平衡。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.The Market for Loanable Funds可贷资金市场可贷资金市场uThe supply of loanable funds comes from national saving(S).可贷资金的供给来源于国民储蓄（可贷资金的供给来源于国民储蓄（S）。）。uThe demand for loanable funds comes from dom

7、estic investment(I)and net capital outflow(NCO).对可贷资金的需求来源于国内投资（对可贷资金的需求来源于国内投资（I）与净资与净资本外流（本外流（NCO）。）。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.The Market for Loanable FundsuThe supply and demand for loanable funds depend on the real interest rate.uA higher real interest r

8、ate encourages people to save and raises the quantity of loanable funds supplied.uThe interest rate adjusts to bring the supply and demand for loanable funds into balance.Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.可贷资金市场可贷资金市场u可贷资金的供给和需求取决于实际利可贷资金的供给和需求取决于实际利率。率。u更高的实际利率鼓励人们

9、储蓄，提高更高的实际利率鼓励人们储蓄，提高可贷资金的供給量。可贷资金的供給量。u利率调整直至可贷资金供求平衡。利率调整直至可贷资金供求平衡。Figure 1 The Market for Loanable FundsQuantity ofLoanable FundsRealInterestRateSupply of loanable funds(from national saving)Demand for loanablefunds(for domesticinvestment and netcapital outflow)EquilibriumquantityEquilibriumreal

10、 interestrateHarcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.图图1.可贷资金市场可贷资金市场可贷资金量可贷资金量实际利率实际利率可贷资金需求可贷资金需求(来自国内投资来自国内投资与净资本外流与净资本外流)可贷资金供给可贷资金供给 （来自国民储蓄（来自国民储蓄)均衡数量均衡数量 均衡的均衡的 实际利率实际利率Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.The Market for Loanable Fun

11、ds可贷资金量可贷资金量At the equilibrium interest rate,the amount that people want to save exactly balances the desired quantities of domestic investment and net capital outflow.在均衡利率时，人们想储蓄的量正好与合在均衡利率时，人们想储蓄的量正好与合意的国内投资和净资本外流量平衡。意的国内投资和净资本外流量平衡。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,

12、Inc.The Market for Foreign-Currency ExchangeuThe two sides of the foreign-currency exchange market are represented by NCO and NX.uNCO represents the imbalance between the purchases and sales of capital assets.uNX represents the imbalance between exports and imports of goods and services.Harcourt,Inc

13、.items and derived items copyright 2001 by Harcourt,Inc.外汇市场外汇市场uNCO和和NX代表外汇市场的双方代表外汇市场的双方。uNCO 代表国外资本资产购买与出售之代表国外资本资产购买与出售之间的不平衡。间的不平衡。uNX 代表物品与劳务出口和进口之间的代表物品与劳务出口和进口之间的不平衡。不平衡。Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.The Market for Foreign-Currency ExchangeuIn the market

14、 for foreign-currency exchange,U.S.dollars are traded for foreign currencies.uFor an economy as a whole,NCO and NX must balance each other out,or:NCO=NXHarcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.外汇市场外汇市场u在外汇市场上，美元和其他货币进行在外汇市场上，美元和其他货币进行交易。交易。u从经济总体上看，从经济总体上看，NCO 和和 NX 必然必然平衡

15、，即平衡，即NCO=NXHarcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.The Market for Foreign-Currency Exchange外汇市场外汇市场The price that balances the supply and demand for foreign-currency is the real exchange rate.实际汇率实际汇率使外汇市场供需平衡的使外汇市场供需平衡的价格。价格。Harcourt,Inc.items and derived items copyrigh

16、t 2001 by Harcourt,Inc.The Market for Foreign-Currency ExchangeuThe demand curve for foreign currency is downward sloping because a higher exchange rate makes domestic goods more expensive.uThe supply curve is vertical because the quantity of dollars supplied for net capital outflow is unrelated to the real exchange rate.Harcourt,Inc.items and derived items copyright 2001 by Harcourt,Inc.外汇市场外汇市场u需求曲线是下倾的，这是因为较高的需求曲线是下倾的，这是因为较高的汇率使国内生产的物品更昂贵。汇率使国内生产的物品更昂贵。u供给曲线是垂直的，这是因为净资本供给曲线是垂直的，这是因为净资本外流的美元供給