《高级宏观经济学幻灯片chapter-6..》由会员分享，可在线阅读，更多相关《高级宏观经济学幻灯片chapter-6..（36页珍藏版）》请在金锄头文库上搜索。
1、Chapter 6 Microeconomic Foundations of Incomplete Nominal Adjustment,周泳宏 ,introduction,The sluggish adjustment of nominal wages and prices is central to Keynesian models. Investigating the microeconomic foundations of that sluggish adjustment is necessary for making the models fully specified But si
2、mply introducing some departure from perfect markets is not enough to imply that nominal disturbances matter,Any microeconomic basis for failure of the classical dichotomy requires some kind of nominal imperfection Classical Dichotomy Monetary disturbances cause all nominal prices and wages to chang
3、e, leaving the real equilibrium unchanged,We examine three nominal imperfections Part A Lucas(1972) and Phelps(1970) The nominal imperfection is that producers do not observe the aggregate price level Part B Monetary shocks have real effects because not all prices or wages are adjusted simultaneousl
4、y Part C Small costs of changing nominal prices or wages Other small friction in nominal adjustment,Part A,The Lucas Imperfect-Information Model,Introduction,When a producer observes a change in the price of his or her product, he or she does not know whether it reflects a change in the goods relati
5、ve price or a change in the aggregate price level A change in the relative price alters the optimal amount to produce A change in the aggregate price level leaves optimal production unchanged,6.1 the case of perfect information,（1）Producer Behavior Representative of a typical good i Qi: the amount h
6、e or she produces Li: the amount that the individual works Ci: the individuals consumption P: the price of the market basket of goods an index of the prices of all goods,The individuals consumption equals his or her real income,Utility depends positively on consumption and negatively on the amount w
7、orked P is given,The individuals labor supply and production are increasing in the relative price of his or her product,（2）Demand The demand for a given good is assumed to depend on three factors: real income, the goods relative price, and a random disturbance to preferences The demand for good i is
8、:,y: the log aggregate real income z: the shock to the demand. The zis have a mean of zero across goods. :the elasticity of demand,y is assumed to equal the average across goods of the qis and P is the average of the pis,The aggregate demand side of the model There are various interpretations of thi
9、s equation There is an inverse relationship between the price level and output m should be thought of as a generic variable affecting aggregate demand rather than as money,（3）Equilibrium Demand per producer equal supply,In a case of perfect information, money is neutral: an increase in m leads to an
10、 increase in p. No real variables are affected,6.2 the case of imperfect information,Defining the relative price of good i by ri The individual does not observe ri, but must estimate it given the observation of pi,Rational expectations the producer finds the expectation of ri given pi rationally,Ind
11、ividuals problem Prove it The fraction of the departure of the pi from its mean that is estimated to be due to the departure of ri from its mean is,When two variables are jointly normally distributed, the expectation of one is a linear function of the observation of the other,Lucas supply curve,Luca
12、s supply curve the departure of output from its normal level (which is zero) is an increasing function of the surprise in the price level,Equilibrium,The component of aggregate demand that is observed, E(m), affects only prices, but the component that is not observed, m-E(m), has real effects,Taking
13、 the expectations of both sides,The expression of b,The expression of b,b is increasing in Vz and decreasing in Vm The special case:,6.3 Implications and Limitations,The Phillips Curve and the Lucas Critique Lucass model implies that unexpectedly high realizations of aggregate demand lead to both hi
14、gher output and higher-than-expected prices The model implies a positive association between output and inflation,An example,White noise,a random walk with drift,Phillips curve,However, the statistical relationship between output and inflation may change if policymakers attempt to take advantage of
15、it,Phillips curve a positive relationship between output and inflation,Lucas critique,Expectations are likely to be important to many relationships among aggregate variables, and changes in policy are likely to affect those expectations If policymakers attempt to take advantage of statistical relati
16、onships, effects operating through expectations may cause the relationships to break down,Anticipated and Unanticipated money,Only unobserved aggregate demand shocks have real effects Monetary policy can stabilize output only if policymakers have information that is not available to private agents Any portion of policy that is a response to publicly available informationsuch as interest rates, the unemployment rate, or the index of leadi
