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。
