高鸿业(宏观经济学)第版-第十三章
西方经济学高鸿业主编第13章课后...
西方经济学高鸿业主编第13章课后习题答案（Western economics, Gao Hongye, editor, thirteenth chapters, after-schoolExercises answer）1. in the two sector of the economy, equilibrium occurs when(C).A. actual savings equals actual investment;B. actual consumption plus actual investment equals output value;C. plans to save is equal to planned investment;D. total investment equals the income of the enterprise sector.2. when the consumption function is C = Aby (a>0,0<b<1), which showed that the average propensity to consume (A).A. is greater than marginal propensity to consume;B. is less than marginal propensity to consume;C. equals marginal propensity to consume; three cases aboveD. are possible.3., if the marginal propensity to save is 0.3, the investment expenditure will increase by 6 billion yuan, which will lead to an increase in the balanced income GDP (D).A. 2 billion yuan;B. 6 billion yuan;C. 18 billion yuan;D.20 billion yuan.4., in the balanced output level, whether the planned inventory investment and unplanned inventory investment must be zero?Answer: when a balanced production level is reached, the planned inventory investment is generally not zero, rather than the planned inventory investment must be zero. This is because the planned inventory investment is part of the planned investment, and the balanced output equals the output of the consumption plus planned investment, so the planned inventory is not necessarily zero. When the planned inventory increases, the inventory investment is greater than zero; when the planned inventory decreases, the inventory investment is less than zero. It should be pointed out that the stock is the stock, the stock investment is the flow, and the stock investment refers to the stock change. At the equilibrium level of output and inventory investment plan is part of a plan to invest, it is not zero, but the non planned inventory investment must be zero, if unplanned inventory investment is not zero, then it is not a balanced output. For example, enterprises wrongly estimated the situation, exceeded the market demand and produced more products, resulting in unplanned inventory investment.5. can the marginal propensity to consume and the average propensity to consume be always greater than zero and less than 1?Answer: consumption tendency is the relation between consumption expenditure and income, also called consumption function. The relationship between consumption expenditure and income can be studied from two aspects, one is the relationship between consumption expenditure and income variables, this is the marginal propensity to consume (can use the formula MPC = y or MPC = delta C delta dcdy), two is to investigate certainincome level of consumer spending in the relationship between the quantity and the this is the amount of income, the average propensity to consume (can use the formula APC = CY). The marginal propensity to consume is greater than zero and less than 1 of the total, because generally, increased consumer income, not only does not increase consumption is MPC = delta C delta y = 0, also won't increase revenue to increase consumption, the general situation is a part for increasing consumption, the other part is used to increase savings, i.e. y = C + delta delta delta s, therefore, delta C delta y + delta s delta y = 1, so, delta C delta y = 1 delta s delta y. As long as Delta s, delta y is not equal to 1 or 0, there are 0 < C, delta y < 1. However, the average propensity to consume is not always greater than zero, but less than 1. When people earn very little or even zero, they have to consume, even if they borrow money. Then the average propensity to consume will be greater than 1.6. what is Keynes's law and what is the social and economic background put forward by Keynes's law?Answer: the so-called Keynes Law refers to, no matter how much for the demand, economic system can provide the supply amount corresponding to the same price, that is to say the total social demand changes, will only cause the yield and income changes, until the supply and demand are equal, without causing a price change. This law is the background of Keynes's writing, "employment, interest and money" a book, the 1929 and 1933 in the western world economic depression, a large number of unemployed workers, a large number of idle resources. In this case, the increase in aggregate social demand will only makeuse of idle resources and increase production, rather than raise resource prices, so that product costs and prices can remain largely the same. The Keynes's law is thought to be suitable for short-term analysis. In the short run, prices are volatile and when social demand changes, firms first consider adjusting output rather than variable prices.7. the government purchase and government transfer payment belong to government spending, why the calculation of total demand of national income is only in government purchases excluding government transfer payments, which is why Cig (y = Xm) rather than Cigtr (y = Xm)?Answer: the government has increased transfer payments, although it has an impact on aggregate demand, but this effect is achieved by increasing disposable income and increasing consumer spending. If the transfer payment is included in the aggregate demand, the repeated calculation in the aggregate demand calculation will be formed. For example, the government increases the transfer payment by 1 billion yuan, assuming that the marginal propensity to consume is 0.8, which will increase consumption by 800 million yuan. Here, the first round of aggregate demand increased by 800 million yuan, not 1 billion 800 million yuan. But if the 1 billion yuan transfer payment is also regarded as an increase in aggregate demand, then it is repeated calculation, that is, 1 billion yuan at a time,It's 800 million yuan at a time.8. why some western economists believe that a portion of national income from the rich to the poor will increase thetotal income level? Answer: their reason is that the rich consumption tendency and lower propensity to save is higher, while the poor and high consumption propensity (because of the poor low income, in order to maintain the basic living standards, the proportion of their spending in income must be greater than the rich, so) will be part of the national income from the rich to the poor that can improve the whole society consumption tendency, so as to improve the whole society's total consumption expenditure level, so the total output or total income will increase.9., why is the absolute value of the government expenditure multiplier larger than the absolute value of the government tax multiplier and the government transfer payment multiplier?Answer: the government (purchase) expenditure directly affects total expenditure, the change of both is the same direction. Changes in total expenditure are several times the amount of government purchases. This multiple is the government's purchase multiplier. But taxation does not directly affect total expenditure, which affects consumer spending by changing people's disposable income, and then affects total expenditure. Tax changes are in reverse direction with changes in total expenditure. When taxes increase (tax rates rise or tax base increases), people's disposable income decreases, consumption decreases, and total expenditure decreases. Total expenditure reductions are several times greater than taxes, and vice versa. This multiple is the tax multiplier. Since tax revenue does not directly affect total expenditure, it will affect consumer spending by changing people's disposable income, and then affect total expenditure. Therefore, the absolute value of thetax multiplier is less than the absolute value of the government purchase expenditure. For example, an increase of 1 billion yuan to buy a government, to increase 1 billion yuan of total demand, but the tax 1 billion yuan, will make people more disposable income of 1 billion yuan, if the marginal propensity to consume is 0.8, one begins to increase consumer demand is only 800 million yuan, so the government spending multiplier of the absolute values of it must be greater than the tax multiplier.Government transfer payment impact on total expenditure is similar to tax, also indirectly affect the total expenditure, but also by changing people's disposable income to affect consumer spending and spending; the absolute value and the government transfer payment multiplier and the tax multiplier is as large as the. But unlike taxes, the government transfers payments in the same direction as the government purchases, but the government transfer payment multiplier is smaller than the government purchase multiplier.10. what is the mechanism of the balanced budget multiplier?Answer: a balanced budget multiplier is the ratio of changes in national revenues to changes in government revenues and expenditures when the amount of government revenue and expenditure increases or decreases in the same amount. In theory, the balanced budget multiplier equals 1. That is to say, if the government increases the expenditure of one yuan and increases the tax on one yuan of money, it will increase the national income by one yuan, because the government's expenditure multiplier is larger than the tax multiplier. Ifyou use the formula that is t = delta delta G (assuming that the transfer payment, and income tr constant) change is determined by the total expenditure changes, that is y = C + I + delta delta delta G, delta I assumes that the investment is unchanged, namely = 0, y = C +, delta delta delta G. The delta C = YD = beta (beta delta delta y delta T), therefore, there is y = P (Y - t) + delta G = P (Y - G) + delta (delta T = g for a g), the authors obtainedY (1 - beta) = delta G (1 - beta)Visible, delta y = g = 1 - beta 1 - beta = 1, i.e. balanced budget multiplier (expressed in KB), KB = g, delta y = 1.This conclusion can also be obtained by directly adding the government purchase expenditure multiplier and the tax multiplierKgkt = 11 - beta (1t) + - beta (1t) beta 1 (1t) = 111., why have some of the multipliers in the closed economy become smaller after foreign trade?Answer: in the closed economy, investment and government expenditures increase multiples of the national income increase is 11 - and beta have foreign trade after the multiple became M (11 - beta beta here and M denote the marginal propensity to consume and the marginal propensity to import), obviously the multiplier becomes small, this is mainly due to a part of the increase the income now used to buy imported goods.12. what is the difference between the three ways in which taxes, government purchases and transfer payments affect aggregate demand?Answer: aggregate demand consists of four components: consumer spending, investment spending, government purchases, and net exports.Taxation does not directly affect aggregate demand. It affects consumer spending by changing people's disposable income, and then affects aggregate demand. The change in taxation is in reverse direction with the change in aggregate demand. As taxes increase (tax rates rise or tax base increases), people's disposable income decreases, consumption decreases, and aggregate demand decreases. The decrease in aggregate demand is several times the increase in taxes, and vice versa. This multiple is the tax multiplier.Government purchase expenditure directly affects aggregate demand, and both change in the same direction. Changes in aggregate demand are also several times the amount of government purchases,This multiple is the government's buying multiplier.The impact of government transfer payments on aggregate demand is similar to taxation, which indirectly affects aggregate demand, as well as changes in people's disposable income, thereby affecting consumer spending and aggregate demand. Moreover, the absolute value of the government transfer payment multiplier and the tax multiplier is the same. But unlike taxes,the government transfer payments change in the same way as the government purchases, but the government transfer payment multiplier is smaller than the government purchase multiplier.These three variables (taxes, government purchases and government transfer payments) are variables that the government can control, and policies that control these variables are called fiscal policies. The government can regulate the economic operation through fiscal policy.For example, an increase of $1 in government spending initially increased aggregate demand by $1, as government purchases were directly related to the demand for end products. But increase the transfer payment of 1 dollars and 1 dollars to reduce taxes, just make people disposable income increased by $1, if the marginal propensity to consume is 0.8, while consumer spending increased only $0.8, the $0.8 is $1 increase transfer payments and tax cuts of $1 in the first round of the final product demand increases, the the difference between the government transfer payment and tax multipliers are equal and opposite, the absolute value of the government purchase multiplier is greater than the government transfer payment multiplier and the absolute value of the tax multiplier.The 13. assumption of an economy's consumption function is C = 1000.8yd investment, I = 50, g = 200 government purchase expenditure, government transfer payment tr = 62.5, t = 250 (tax unit for $1 billion).(1) seeking balanced income.(2) try to find the investment multiplier, the government expenditure multiplier, the tax multiplier, the transfer payment multiplier and the balanced budget multiplier.Answer: (1) by equationsSolvable y = 1000 ($100 million), so the balanced income level is $100 billion.(2) we can obtain the multiplier value directly according to the formula of the multiplier in the three sector economyInvestment Multiplier: ki = 11 - beta = 110.8 = 5Government spending multiplier: kg = 5 (equal to the investment multiplier)Tax Multiplier: KT = - 1 - beta beta = 0.810.8 = 4Transfer Payment Multiplier: KTR = 1 beta beta = 0.810.8 = 4The balanced budget multiplier is equal to the sum of government spending (purchase) multiplier and tax multiplierKB = Kgkt = 5 (4) = 1In the 14. part, assuming that the society to achieve the needs of full employment, national income is 1200, ask: (1) increase in government purchases; (2) to reduce taxes; (3) with the same amount of increase in government purchases and taxes (in order to balance the budget) to achieve full employment, the amountof how much?Answer: the question clearly uses a variety of multipliers. Originally balanced income is 1000, now need to reach 1200, then the gap = y = 200.(1) increase the government purchase of delta G = ykG = 2005 = 40.(2) decrease of tax = t = 200|kt| = 2004 = 50.(3) from the balanced budget multiplier equals 1, we can see that 200 of the government purchases and 200 of the tax revenue can achieve full employment.15. assume that the consumption function of economy and society in a C = 300.8yd, net tax total tax minus government transfer payment amount after TN = 50, investment I = 60, g = 50 government purchase expenditure and net export balance that exports minus imports after NX = 500.05y, for: (1) balance of income; (2) in the equilibrium level of income on the net export balance; (3) investment multiplier; (4) investment from 60 to 70 when the balance of income and net export balance; (5) when the equilibrium income net exports from NX = 50 to NX = 40 0.05y - 0.05y and net export balance.Answer: (1) disposable income: YD = Ytn = Y50Consumption: C = 300.8 (Y50)= 300.8y40= 0.8y10Equilibrium income: y = Cignx= 0.8y106050500.05y= 0.75y150The solution is y = 1500.25 = 600, i.e., the equilibrium income is 600.(2) net export balance:Nx = 500.05y = 500.05 x 600 = 20(3) investment multiplier ki = 110.80.05 = 4.(4) when the investment increased from 60 to 70, there wereY = Cignx= 0.8y107050500.05y= 0.75y160The solution is y = 1600.25 = 640, i.e., the equilibrium income is 640.Net export balance:Nx = 500.05y = 500.05 x 640 = 5032 = 18(5) the equilibrium income of the net export function changed from NX = 50 - 0.05y to NX = 40 - 0.05y:Y = Cignx= 0.8y106050400.05y= 0.75y140The solution is y = 1400.25 = 560, i.e., the equilibrium income is 560.Net export balance:Nx = 400.05y = 400.05 560 40 28×＝－＝12。
高鸿业版《西方经济学》(宏观部分)第十三章：简单国民收入决定.
用E代表支出，用Y代表收入。若支出<收入（需求<供给），则企业非意 愿存货投资IU>0 企业就要削减生产，若支出>收入（需求>供给），则企 业非意愿存货投资IU<0 企业就要扩大生产
E
直线上任意一点均为E=y
E
150
Y=c+s E=c+i
收入=100 100
利率变动对储蓄会产生替代效应与收入效应。得率引起的用 未来消费代替现期消费称为替代效应，利率引起的未来收入 的增加称为收入效应。
2、价格水平
这里指的是整体价格水平对消费的影响，而不是指个别商品 价格对消费的影响。如果消费者只注意到货币收入增加，而 忽弱了物价的上升，则会误以为实际收入增加，从而平均消 费倾向也会上升，这种现象称之为消费者的“货币幻觉” （Monetary illusion）。
5、流动资产
随着一个家庭拥有流动资产的增加，它增加流动资产的迫切 性递减，这样，拥有流动资产多的家庭其消费倾向要高于拥 有流动资产少的家庭。
6、减税政策
R·巴罗认为减税对消费并没有影响，因为减税并不会影响持 久收入，也就不会影响消费，人们只是把减税引起的收入增 加储蓄起来以支付以后的增税，只是增加了储蓄。但实证研 究表明：人们一般不重视未来增税，认为那是以后几代人的 事。
第十三章 简单国民收入决定理论
学习目的与要求 通过本章的学习，了解和掌握简单的国民收入决定的
基本概念、基本原理，为了解和掌握整个宏观经济学 的核心理论——国民收入决定论打下基础。 重点与难点 均衡产出、消费函数与国民收入、乘数理论
宏观经济学的内容体系 国民收入水平的决定分析 凯恩斯主义的全部理论涉及四个市场：产品、货币、
高鸿业的宏观经济学学习讲义
试求：（1）、用定义法计算GDP； （2）、用生产法计算GDP； （3）、用支出法计算GDP； （4）、用收入法计算GDP。
第１３章
国民收入核算习题课
1．设在一个经济中，新创造产品和劳务销售价格NDP＝1000，政府税收T＝ 100，政府开支G＝90，个人消费支出C＝810；个人储蓄S＝90，投资I＝100。 试计算政府财政盈余，并表示出财政盈余与储蓄及投资的关系。 2．一个棉农一年生产1000元籽棉，他售给轧棉厂加工成1400元棉花，轧棉厂又 将这些棉花售给纺纱厂加工成棉纱… … 。根据下表分别计算总产值和总增加 值。并分析为什么不易用总产值来衡量一国的财富。
第六节
名义ＧＤＰ和实际ＧＤＰ
一、名义GDP和实际GDP的概念 名义GDP是指，用生产物品和劳务的当年价格计算的全部最终 产品的市场价值； 实际GDP是指，用从前某一年作为基期的价格计算出来的全部 最终产品的市场价值。 二、例题（参见教材P425） 三、若干常用字母的记号含义
典型习题
教材P429第9题：从下表资料中找出： ①国民收入；②国内生产净值；③国 内生产总值；④个人收入；⑤个人可支配收入；⑥个人储蓄。 求解提示： 此题中，政府和企业的转移支付是指政府 和企业都针对居民的转移支付，任何其它形式 的理解将不利于求解本问题。 注意，本题的求解和尹伯成的《宏观习题 指南》提供的解略有不同。 ①国民收入＝雇员薪金＋企业利息支付＋ 个人租金收入＋公司利润＋非公司企业主收 入＋社会保险税； ②国内生产净值＝国民收入＋间接税； ③国内生产总值＝国内生产净值＋折旧； ④个人收入＝国民收入−(公司利润＋社会 保险税)＋政府支付利息＋政府转移支付＋红 利； ⑤个人可支配收入＝个人收入−个人所得 税 ⑥个人储蓄＝个人可支配收入−消费者支 付利息−个人消费支出。
高鸿业《宏观经济学》课后习题答案第十三章习题答案
高鸿业《宏观经济学》课后习题答案第十三章习题答案第十三章简单国民收入决定理论1.在两部门经济中，均衡发生于( )之时。
A.实际储蓄等于实际投资；B.实际消费加实际投资等于产出值；C.计划储蓄等于计划投资；D.总投资等于企业部门的收入。
解答：C2.当消费函数为c＝a＋by(a0,01)，这表明，平均消费倾向( )。
A.大于边际消费倾向；B.小于边际消费倾向；C.等于边际消费倾向；D.以上三种情况都可能。
解答：A3.如果边际储蓄倾向为0.3，投资支出增加60亿元，这将导致均衡收入GDP增加( )。
A.20亿元；B.60亿元；C.180亿元；D.200亿元。
解答：D4.在均衡产出水平上，是否计划存货投资和非计划存货投资都必然为零？解答：当处于均衡产出水平时，计划存货投资一般不为零，而非计划存货投资必然为零。
这是因为计划存货投资是计划投资的一部分，而均衡产出就是等于消费加计划投资的产出，因此计划存货不一定是零。
计划存货增加时，存货投资就大于零；计划存货减少时，存货投资就小于零。
需要指出的是，存货是存量，存货投资是流量，存货投资是指存货的变动。
在均衡产出水平上，计划存货投资是计划投资的一部分，它不一定是零，但是非计划存货投资一定是零，如果非计划存货投资不是零，那就不是均衡产出了。
比方说，企业错误估计了形势，超出市场需要而多生产了产品，就造成了非计划存货投资。
5.能否说边际消费倾向和平均消费倾向总是大于零而小于1？解答：消费倾向就是消费支出和收入的关系，又称消费函数。
消费支出和收入的关系可以从两个方面加以考察，一是考察消费支出变动量和收入变动量的关系，这就是边际消费倾Δcdc向(可以用公式MPC＝或MPC＝表示)，二是考察一定收入水平上消费支出量和该收入Δydyc量的关系，这就是平均消费倾向(可以用公式APC＝表示)。
边际消费倾向总大于零而小于1，yΔc因为一般说来，消费者增加收入后，既不会不增加消费即MPC＝＝0，也不会把增加的收Δy入全用于增加消费，一般情况是一部分用于增加消费，另一部分用于增加储蓄，即Δy＝ΔcΔcΔsΔcΔsΔsΔc＋Δs，因此，＋＝1，所以，＝1－。
高鸿业宏观经济学第13章
s
s= -a +（ - b ） 1 y
s = - a + (1-b) y
（1＞b＞0）
0 线形储蓄函数
y
西方经济学· 宏观· 第13章 12
5.储蓄倾向
储蓄倾向：储蓄与收入的比率。
平均储蓄倾向：储蓄总量与收入总量的比率, APS。 average propensity to save 储蓄与收入之比＝储蓄/收入 APS = s / y 收入100元中，80元用于消费，其余20元用于储蓄，平均
如果中年人比例增大，消费倾向会下降。反之会增加。 基本结论：C=aWR+cYL 其中，WR为实际财富；a为财富的边际消费倾向即每年消费的财富的 比例 ；YL为工作收入；c为工作收入的边际消费倾向。
遗产的存在，会使得储蓄增加。 社会保障体系健全，储蓄会减少。 人生安全风险加大，储蓄会减少。
西方经济学· 宏观· 第13章 20
入。
结论： 家庭会使现期消费等于永久收入。 现期收入>永久收入时，家庭会增加储蓄； 现期收入<永久收入时，家庭会动用储蓄。
西方经济学· 宏观· 第13章 22
莫迪里安尼简介
莫迪里安尼（1918－）长期担任麻省理工学院 教授，在经济学流派上属于拥护凯恩斯主义的新古
典综合派。他除了在消费函数理论方面作出了杰出
在上章国民收入核算中，从事后的实际情况看，I = S，是
必然的结果。是会计结果。
西方经济学· 宏观· 第13章 4
二、凯恩斯的消费理论
1.消费：一个国家(或地区)，一定时期内， 居民个人(或家庭)，为满足消费欲望， 而用于购买消费品和劳务的所有支出。 2.消费函数：指消费支出与决定消费诸因素之间的依存关 系。（广义上的概念）
西方经济学_高鸿业(宏观部分)第四版课后答案
第十三章简单国民收入决定理论3、依据哪种消费理论，一个暂时性减税对消费影响最大？依据哪种消费理论，社会保障金的一个永久性上升对消费影响最大？依据哪种消费理论，持续较高的失业保险金对消费影响最大？解答：依据凯恩斯消费理论，一个暂时性减税会增加人们当前收入，因而对消费影响最大,凯恩斯认为消费是收入的函数，减税使得收入增加进而使得消费相应的增加。
其他的消费理论认为如果减税只是临时性的，则消费不会受到很大的影响，收入的变动对消费的影响是较小的。
依据生命周期理论，社会保障金的一个永久性上升可以减少老年时代的后顾之忧，减少当前为退休后生活准备的储蓄，因而会增加消费。
依据持久收入消费理论，持续较高的失业保险金等于增加了持久收入，因而可增加消费。
4、哪种消费理论预言总储蓄将依赖与人口中退休人员和年轻人的比例？这种关系是什么？哪种理论预言消费将不会随经济的繁荣与衰退做太大变化？为什么？解答：生命周期理论认为，年轻人要为自己年老生活作储蓄准备，因此，年轻人对退休人员比例提高时，总储蓄会增加.反之，退休人员对年轻人比例上升，总储蓄会下降，因为退休人员不储蓄，而消耗已有储蓄.持久收入假说认为，消费行为与持久收入紧密相关，而与当期收入较少有关联，即消费不会随经济的繁荣与衰退作太大变化。
相对收入消费理论认为消费不会随经济的繁荣和衰退做太大变化，这种理论认为消费者会受自己过去的消费水平的影响来决定消费，当期消费是相对固定的。
依照人们习惯，增加消费容易，减少消费很难。
因此从短期来看，在经济波动过程中，收入增加时低水平收入者的消费会增加，但收入减少时消费水平的降低则很有限。
5、假设你和你邻居的收入完全一样，不过你比她更健康从而预期有更长的寿命。
那么，你的消费水平将高于还是低于他的消费水平？为什么？解答：可以根据生命周期假说来分析此题.分两种情况讨论：(1)当你和你的邻居预期寿命小于工作年限WL ，即未到退休就已结束生命时，尽管你比邻居长寿写，但两人年年都可能把年收入YL 消费完，两人的消费会一样多。
(完整版)高鸿业《宏观经济学》课后习题答案第十三章习题答案
第十三章 简单国民收入决定理论1.在两部门经济中，均衡发生于( )之时。
A.实际储蓄等于实际投资； B.实际消费加实际投资等于产出值；C.计划储蓄等于计划投资；D.总投资等于企业部门的收入。
解答：C2.当消费函数为c ＝a ＋by(a>0,0<b<1)，这表明，平均消费倾向( )。
A .大于边际消费倾向；B .小于边际消费倾向；C .等于边际消费倾向；D .以上三种情况都可能。
解答：A3.如果边际储蓄倾向为0.3，投资支出增加60亿元，这将导致均衡收入GDP 增加 ( )。
A . 20亿元；B . 60亿元；C . 180亿元；D . 200亿元。
解答：D4.在均衡产出水平上，是否计划存货投资和非计划存货投资都必然为零？解答：当处于均衡产出水平时，计划存货投资一般不为零，而非计划存货投资必然为零。
这是因为计划存货投资是计划投资的一部分，而均衡产出就是等于消费加计划投资的产出，因此计划存货不一定是零。
计划存货增加时，存货投资就大于零；计划存货减少时，存货投资就小于零。
需要指出的是，存货是存量，存货投资是流量，存货投资是指存货的变动。
在均衡产出水平上，计划存货投资是计划投资的一部分，它不一定是零，但是非计划存货投资一定是零，如果非计划存货投资不是零，那就不是均衡产出了。
比方说，企业错误估计了形势，超出市场需要而多生产了产品，就造成了非计划存货投资。
5.能否说边际消费倾向和平均消费倾向总是大于零而小于1？解答：消费倾向就是消费支出和收入的关系，又称消费函数。
消费支出和收入的关系可以从两个方面加以考察，一是考察消费支出变动量和收入变动量的关系，这就是边际消费倾向(可以用公式MPC ＝Δc Δy 或MPC ＝d c d y表示)，二是考察一定收入水平上消费支出量和该收入量的关系，这就是平均消费倾向(可以用公式APC ＝c y表示)。
边际消费倾向总大于零而小于1，因为一般说来，消费者增加收入后，既不会不增加消费即MPC ＝Δc Δy＝0，也不会把增加的收入全用于增加消费，一般情况是一部分用于增加消费，另一部分用于增加储蓄，即Δy＝Δc ＋Δs ，因此，Δc Δy ＋Δs Δy ＝1，所以，Δc Δy ＝1－Δs Δy 。
宏观经济学复习提纲
宏观经济学复习提纲⾼鸿业《宏观经济学》复习提纲⼀、宏观经济学基本框架⼆、各章知识点分析第12章国民收⼊核算⼀、了解与识记1、宏观经济学研究对象和研究⽅法：即均衡国民收⼊理论和总量分析⽅法2、GDP的内涵，（知道什么项⽬计⼊GDP，GDP与GNP的关系，实际GDP与名义GDP的关系）3、核算国民收⼊的三种⽅法（⽀出法、收⼊法、增殖法需要了解）4、中间产品与最终产品区别5、GDP折算数⼆、理解与分析1、国民收⼊各个核算指标之间的关系第13章简单国民收⼊核算理论⼀、了解与识记1、简单国民收⼊决定理论的含义及简章经济的假设条件2、均衡产出的含义及条件3、凯恩斯的绝对收⼊消费理论（理解与分析消费函数与储蓄函数的关系）4、其他消费理论⼆、理解与分析1、两部门、三部门、四部门（略）国民收⼊的决定及变动（重点）2、两部门、三部门、四部门（略）的各个乘数（重点）第14章产品市场和货币市场的⼀般均衡（重点章节）⼀、了解与识记1、经济学投资的概念、投资函数、投资的影响因素2、IS曲线的含义3、货币需求函数、交易需求及投机需求4、凯恩斯陷阱、古典极端5、LM曲线的含义6、货币的供给（名义供给与实际供给）⼆、理解与分析1、两部门、三部门IS曲线（⽅程）及其移动（IS曲线的推导——图形分析）2、均衡利率的决定及其变动（LM曲线的推导——图形分析）3、产品市场和货币市场⼀般均衡及均衡的变动4、失衡的区域及失衡的恢复第15章宏观经济政策分析（重点章节）⼀、了解与识记1、财政政策和货币政策的影响⼆、理解与分析1、财政政策效果的IS-LM图形分析（⼀般情形、极端情形）2、货币政策效果的IS-LM图形分析（⼀般情形、极端情形）3、挤出效应的内涵、图形分析、影响因素。
4、两种政策混合使⽤的政策效应第16章宏观经济政策实践（重点章节）⼀、了解与识记1、⾃然失业率（结合第18章充分理解）2、财政政策、政策⼯具（哪些是扩张性的，哪些是紧缩性的？）、局限性3、财政政策和货币政策实施的总原则是什么？——“逆经济风向⾏事”4、证券市场基础知识（证券价格决定，买空（多头），卖空（空头），⼀级市场，⼆级市场，主板市场，⼆板市场）（可以略看）⼆、理解与分析1、经济政策的⽬标及相互关系⽬标：经济持续均衡增长、充分就业、价格稳定、国际收⽀平衡关系：四个⽬标是⽭盾统⼀的。