第7章 非均衡分析的货币理论(货币理论与政策-上海外贸学院,王志伟)

《当代货币金融理论》金融学院系列课程第7章非均衡分析的货币理论Dr.王志伟Jerald_wang@Economics & Change第一节非均衡分析与凯恩斯经济学第二节货币经济的交易结构与货币经济理论Mercer Human Resource Consulting《当代货币金融理论》7-2©COPYRIGHT 2005 by Dr.王志伟第一节非均衡分析与凯恩斯经济学1、传统经济学认为凯恩斯理论是一般均衡理论希克斯商品市场和货币市场均衡的ISLM模型两个市场的均衡决定均衡利率和产出的模型帕廷金四个市场的均衡The Goods Marketand the IS RelationEquilibrium in the goods market exists when production, Y, is equal to the demand for goods, Z.In the simple model (in chapter 3), the interest rate did not affect the demand for goods. The equilibrium condition was given by:()Y C Y T I G=−++Investment, Sales (Y), and the Interest Rate (i)Now, we no longer assume I (investment) is constantWe capture the effects of two factors affecting investment:–The level of sales/income (+)–The interest rate (-)=(,)I I Y iThe Investment Demand ScheduleIncluding interest rates in the model implies thatinvestment spending is endogenousThe investment spending function (9.1) is:I I b i=−–where i is the rate of interest and b measures theresponsiveness of investment spending to theinterest rate–Autonomous investment is IThe Determination of OutputTaking into account the investment relation above, the equilibrium condition in the goods market becomes:()(,)=−++Y C Y T I Y i GWith investment dependent upon interest rates the new AD function (9.2, 9.3) is:()NXG I cTR C A biY t c A AD ++++=−−+≡1–A higher interest rate reduces investment spending which reduces AD for a given level of income –Autonomous investment is still a component of autonomous spendingAWe can derive the IS curve by using the goods market equilibrium condition AD = Y This gives the IS equation (9.5) ()()111αα=−≡−−G G Y A bi c tThe Determination of OutputThe demand for goods isan increasing function ofoutput. Equilibriumrequires that the demandfor goods be equal tooutput.Equilibrium in the GoodsMarketDeriving the ISCurveAn increase in the interestrate decreases the demandfor goods at any level ofoutput.The Effects of an Increaseinthe Interest Rate onOutputDeriving the IS CurveThe Derivation of the ISCurveThe IS Curve Shifts of the IS CurveAn increase in taxes...Financial Marketsand the LM RelationThe interest rate is determined by the equality of the supply of and the demand for money:=$()M YL iM= nominal money stock$YL(i) = demand for money$Y= nominal incomei= nominal interest rateThe Demand for MoneyThe demand for real balances (9.9)L = k Y-hi–depends on the level of real income Y and the interest rate iThe higher the income, the greater the demand for real balancesThe higher the interest rate–the lower the demand for real balances–because the cost of holding money is higherhe Supply of Money, Money Market Equilibrium and the LM CurveThe RBA controls the nominal money supply (M) through OMO The real money supply is 0/3The LM curve shows all combinations of interest rates andincome such that–the demand for real balances is equal to the real moneysupply (i.e. money market equilibrium)Real Money, Real Income,and the Interest RateThe LM relation: In equilibrium, the real money supply is equal to the real money demand, which depends on real income, Y, and the interest rate, i:M PYL i =()Recall: before, we had the same equation but in nominal instead of real terms (nominal income and nominalmoney supply). Dividing both sides by P (the price level) gives us the equation above.Deriving the LM Curve For money market equilibrium, demand for real balances must equal supplyThis is the LM curve in 10.10a⎟⎟⎠⎞⎜⎜⎝⎛−=∴−=P M kY h i hikY P M1Deriving the LM CurveThe Effects of anIncrease in Income on the Interest RateDeriving the LM CurveThe Derivation of theLM CurveShifts of the LM CurveAn increase inmoney...Shifts of the LMCurveThe IS and the LM Relations TogetherEquilibrium in the goods market (IS). Equilibrium in financial markets (LM).When the IS curve intersects the LM curve, both goods and financial markets are in equilibrium.IS relation: Y=−++C Y T I Y i G()(,)LM relation:MP=YL i()The IS-LM Model1、传统经济学认为凯恩斯理论是一般均衡理论新古典综合派认为，凯恩斯分析的是在价格与工资刚性条件下的一个特例。

他们认为，只要工资和价格具有足够的弹性，持续的小于充分就业的均衡状态就不可能存在。

2、非均衡理论创始人克劳尔认为：凯恩斯主要研究经济持续低于充分就业非均衡状态，虽然其采取的是比较静态的方法，但他考察的这种非均衡状态乃是一种产量和就业量波动的动态过程，所以，凯恩斯理论本质上是动态非均衡理论。

3、非均衡分析的基本框架从分析个别交易者在市场中的行为入手分析：在一般均衡理论假设下，各种交易和经济活动实际上是在均衡价格达成之后的状态下进行的，非均衡价格的错误交易不存在；而实际上，绝大多数交易和经济活动是在非均衡价格上进行的。

克劳尔提出了计划超额需求与实际超额需求的概念。

计划超额需求，是只依赖价格而与实际交易无关的超额需求；实际超额需求，是同时考虑价格和其它市场实际交易数量约束的超额需求。

进一步分析：在非均衡价格下交易，总有一部分交易不能实现其供给计划与需求计划。

因为交易者在某市场因种种约束导致销售量低于计划供给量，他在另一市场上的购买量必然会因收入约束而低于计划需求量。