宏观经济学9收入与支出

1、Chapter 9 income and spending 收入和支出nMutual interaction between output and spending nAutonomous spending increase output more than one for one .(multiplier effect)nThe size of the multiplier depends on the marginal propensity to consume and tax rates.n收入和支出具有密切的关系n自发的支出具有乘数效应n乘数效应取决于边际消费倾向和税率nIncreas

2、e in government spending increase aggregate demand and therefore tax collections. But tax collections rise by less than the increase in government spending, so increased government spending increases the budget deficit.n政府支出提高了总需求和税收总额，但少于政府支出的增加额，所以财政赤字增加9-1 总需求与均衡产出Aggregate demand and equilibrium

3、 outputnaggregate demandnAD=C+I+G+NXnequilibrium outputnY=AD=C+I+G+NXnunplanned inventorynIU=Y-ADn总需求n均衡产出n非意愿存货9-2 消费函数和总需求The consumption function and aggregate demandnconsumption function n C=C+cYnThe marginal propensity to consumenThe increase in consumption per unit increase in incomenThe margi

4、nal propensity to saven消费函数n边际消费倾向n边际储蓄倾向消费和储蓄consumption and savingnautonomous spendingndetermined outside the model and specially assumed to be independent of incomen自发支出自发性：n影响变量在模型之外，特别是独立于收入n主要讨论自发性投资、政府支出、税收、转移支付等n公式的推导(193)：nAD=C+I+G+NXn Fig9-1 The Consumption Function and Aggregate DemandFig

5、9-2 Determination of Equilibrium Income and Outputnthe formula for equilibrium outputn194页的图与公式n均衡产出的公式 Equilibrium income and output均衡收入和产出nGiven the intercept, a steeper aggregate demand function , implies a higher level of equilibrium income.nFor a given marginal propensity to consume, a higher l

6、evel of autonomous spending implies a higher level of equilibrium income n两种情形的讨论nA不变，c越大，均衡产出越高nc固定，则A越大，均衡产出越高n结论：C越大，自发总需求越大，则均衡产出越高saving and investment (储蓄和投资)nIn equilibrium, planned investment equals saving.nI=S +（TA-TR-G）- NXn“corn economy”-leftover corn: saved by individuals; corn leftover

7、from government tax collections net of government spending, and any net corn imported from abroad.n在均衡条件下，意愿投资等于储蓄n两部门条件下的公式推导n四部门条件下的分析n公式的推导：n形象的比喻：“谷物经济”9-3 the multiplier (乘数效应)nThe multiplier is the amount by which equilibrium output changes when autonomous aggregate demand increase by 1 unit.n

8、The multiplier is therefore potentially part of the explanation of why output fluctuates.n公式的推导(196页的公式与198页的图)n乘数的概念：n一般性概念：自发性需求增加1个单位时，总产出的变化量。n不考虑政府部门和对外贸易：1/(1-c)n讨论乘数的理由(讨论)9-13Derivation of the Multiplier 94the government sector 政府部门nThe government directly affects the level of equilibrium in

9、come in two separate ways.nGovernment purchases of goods and services.n TR、TA affects the relation between output and income.n政府影响均衡收入水平的两种方式：nG：政府购买是总需求的一部分nTR、TA影响产出与收入、可支配收入之间的关系n公式的推导：n对图的说明(fig 9-4)equilibrium income (均衡收入)na=1/1-c(1-t)nIncome taxes lower the multiplier.n公式推导(200-201页)n结论：收入税的出

10、现降低了乘数效应effects of changes in fiscal policy财政政策变化的效应n政府购买的效应n公式推导(202)n图的说明n(fig9-5 The Effects of an Increase in Government Purchases )n政府转移支付的效应n公式推导n图的说明n两种政策效应的比较 95the budget (财政预算)n预算盈余(budget surplus)预算赤字(budget deficit)nFig 9-5 U.S. Government Budget Deficit as a Percent of GDP, 1901-2002 Fig 9-6 The Budget Surplus政府购买和税收变动对预算的影响(略)nincreased government purcha