克鲁格曼Krugman《国际经济学》中英文课件和习题答案

1、chapter 2 1home has 1200 units of labor available. it can produce two goods, apples and bananas. the unit labor requirement in apple production is 3, while in banana production it is 2. agraph out the production possibilities frontier: bwhat is the opportunity cost of apples in terms of bananas? 5 .

2、 1 lb la a a cin the absence of trade, what would the price of apples in terms of bananas be? in the absence of trade, since labor is the only factor of production and supply decisions are determined by the attempts of individuals to maximize their earnings in a competitive economy, only when will b

3、oth goods be produced. so lblaba /aa /pp1.5 /pp ba 2home is as described in problem 1. there is now also another country, foreign, with a labor force of 800. foreigns unit labor requirement in apple production is 5, while in banana production it is 1. agraph foreigns production possibilities frontie

4、r: bconstruct the world relative supply curve. homes ppf 0 200 400 600 800 200400600800 qapple qbanana foreigns ppf 0 200 400 600 800 1000 80160 240 320 400 q*apple q*banana 3now suppose world relative demand takes the following form: demand for apples/demand for bananas = price of bananas/price of

5、apples. agraph the relative demand curve along with the relative supply curve: abba /pp/dd when the market achieves its equilibrium, we have 1 b a )( d d b a b b a a p p qq qq rd is a hyperbola x y 1 bwhat is the equilibrium relative price of apples? the equilibrium relative price of apples is deter

6、mined by the intersection of the rd and rs curves. rd: y x 1 rs: 5 5 , 5 . 1 5 . 1 , 5 . 0( 5 . 0 )5 . 0 , 0 y y y x x x 25 . 0yx 2/bpap ee cdescribe the pattern of trade. ba b e a e bapppppp/ in this two-country world, home will specialize in the apple production, export apples and import bananas.

7、foreign will specialize in the banana production, export bananas and import apples. dshow that both home and foreign gain from trade. international trade allows home and foreign to consume anywhere within the colored lines, which lie outside the countries production possibility frontiers. and the in

8、direct method, specializing in producing only one production then trade with other country, is a more efficient method than direct production. in the absence of trade, home could gain three bananas by foregoing two apples, and foreign could gain by one foregoing five bananas. trade allows each count

9、ry to trade two bananas for one apple. home could then gain four bananas by foregoing two apples while foreign could gain one apple by foregoing only two bananas. so both home and foreign gain from trade. 4suppose that instead of 1200 workers, home had 2400. find the equilibrium relative price. what

10、 can you say about the efficiency of world production and the division of the gains from trade between home and foreign in this case? rd: y x 1 rs: 5 5 , 5 . 1 5 . 1 , 1 ( 1 ) 1 , 0 y y y x x x 5 . 1 3 2 yx 5 . 1/bpap ee in this case, foreign will specialize in the banana production, export bananas

11、and import apples. but home will produce bananas and apples at the same time. and the opportunity cost of bananas in terms of apples for home remains the same. so home neither gains nor loses but foreign gains from trade. 5suppose that home has 2400 workers, but they are only half as production in b

12、oth industries as we have been assuming, construct the world relative supply curve and determine the equilibrium relative price. how do the gains from trade compare with those in the case described in problem 4? in this case, the labor is doubled while the productivity of labor is halved, so the eff

13、ective laborremains the same. so the answer is similar to that in 3. and both home and foreign can gain from trade. but foreign gains lesser compare with that in the case 4. 6 ”korean workers earn only $2.50 an hour; if we allow korea to export as much as it likes to the united states, our workers w

14、ill be forced down to the same level. you cant import a $5 shirt without importing the $2.50 wage that goes with it.” discuss. in fact, relative wage rate is determined by comparative productivity and the relative demand for goods. koreas low wage reflects the fact that korea is less productive than

15、 the united states in most industries. actually, trade with a less productive, low wage country can raise the welfare and standard of living of countries with high productivity, such as united states. so this pauper labor argument is wrong. 7japanese labor productivity is roughly the same as that of

16、 the united states in the manufacturing sector (higher in some industries, lower in others), while the united states, is still considerably more productive in the service sector. but most services are non-traded. some analysts have argued that this poses a problem for the united states, because our

17、comparative advantage lies in things we cannot sell on world markets. what is wrong with this argument? the competitive advantage of any industry depends on both the relative productivities of the industries and the relative wages across industries. so there are four aspects should be taken into acc

18、ount before we reach conclusion: both the industries and service sectors of japan and u.s., not just the two service sectors. so this statement does not bade on the reasonable logic. 8anyone who has visited japan knows it is an incredibly expensive place; although japanese workers earn about the sam

19、e as their u.s. counterparts, the purchasing power of their incomes is about one-third less. extend your discussing from question 7 to explain this observation. (hint: think about wages and the implied prices of non-trade goods.) the relative higher purchasing power of u.s. is sustained and maintain

20、ed by its considerably higher productivity in services. because most of those services are non-traded, japanese could not benefit from those lower service costs. and u.s. does not have to face a lower international price of services. so the purchasing power of japanese is just one-third of their u.s

21、. counterparts. 9how does the fact that many goods are non-traded affect the extent of possible gains from trade? actually the gains from trade depended on the proportion of non-traded goods. the gains will increase as the proportion of non-traded goods decrease. 10we have focused on the case of tra

22、de involving only two countries. suppose that there are many countries capable of producing two goods, and that each country has only one factor of production, labor. what could we say about the pattern of production and in this case? (hint: try constructing the world relative supply curve.) any cou

23、ntries to the left of the intersection of the relative demand and relative supply curves export the good in which they have a comparative advantage relative to any country to the right of the intersection. if the intersection occurs in a horizontal portion then the country with that price ratio prod

24、uces both goods. chapter 3 1.in 1986, the price of oil on world markets dropped sharply. since the united states is an oil-importing country, this was widely regarded as good for the u.s. economy. yet in texas and louisiana 1986 was a year of economic decline. why? it can deduce that texas and louis

25、iana are oil-producing states of united states. so when the price of oil on world markets declined, the real wage of this industry fell in terms of other goods. this might be the reason of economic decline in these two states in 1986. 2。an economy can produce good 1 using labor and capital and good

26、2 using labor and land. the total supply of labor is 100 units. given the supply of capital, the outputs of the two goods depends on labor input as follows: to analyze the economys production possibility frontier, consider how the output mix changes as labor is shifted between the two sectors. a.gra

27、ph the production functions for good 1 and good 2. ),(),( 22221111 lkqqlkqq p pr ro od du uc ct ti io on n f fu un nc ct ti io on n f fo or r g go oo od d 1 1 0 0 2 25 5. .1 1 3 38 8. .1 1 4 48 8. .6 6 5 57 7. .5 5 6 66 6 7 73 3. .6 6 8 80 0. .7 7 8 87 7. .4 4 9 93 3. .9 9 1 10 00 0 0 10 20 30 40 50

28、 60 70 80 90 100 0102030405060708090100 l la ab bo or r i in np pu ut t f fo or r g go oo od d 1 1 o ou ut tp pu ut t p pr ro od du uc ct ti io on n f fu un nc ct ti io on n f fo or r g go oo od d 2 2 0 0 3 39 9. .8 8 5 52 2. .5 5 6 61 1. .8 8 6 69 9. .3 3 7 75 5. .8 8 8 81 1. .5 5 8 86 6. .7 7 9 91

29、 1. .4 4 9 95 5. .5 5 1 10 00 0 0 10 20 30 40 50 60 70 80 90 100 0102030405060708090100 l la ab bo or r i in np pu ut t f fo or r g go oo od d 2 2 o ou ut tp pu ut t b.graph the production possibility frontier. why is it curved? q1 q2 l1 l2 ppf ),( 2222 lkqq ),( 1111 lkqq 100 100 the ppf is curved d

30、ue to declining marginal product of labor in each good. the total labor supply is fixed. so as l1 rises, mpl1 falls; correspondingly, as l2 falls, mpl2 rises. so pp gets steeper as we move down it to the right. 2.the marginal product of labor curves corresponding to the production functions in probl

31、em2 are as follows: a.suppose that the price of good 2 relative to that of good 1 is 2. determine graphically the wage rate and the allocation of labor between the two sectors. with the assumption that labor is freely mobile between sectors, it will move from the low-wage sector to the high-wage sec

32、tor until wages are equalized. so in equilibrium, the wage rate is equal to the value of labors marginal product. 2/ 122211 pppmplpmpl the abscissa of point of intersection illustrated above should be between (20, 30). since we only have to find out the approximate answer, linear function could be e

33、mployed. the labor allocation between the sectors is approximately l1=27 and l2=73. the wage rate is approximately 0.98. b.using the graph drawn for problem 2, determine the output of each sector. then confirm graphically that the slop of the production possibility frontier at that point equals the

34、relative price. q1 q2 l1 l2 ppf ),( 2222 lkqq ),( 1111 lkqq 100 100 2 1 slope the relative price is p2/p1=2 and we have got the approximate labor allocation, so we can employ the linear function again to calculate the approximate output of each sector: q1=44 and q2=90. c.suppose that the relative pr

35、ice of good 2 falls to 1. repeat (a) and (b). the relative decline in the price of good 2 caused labor to be reallocated: labor is drawn out of production of good 2 and enters production of good 1 (1=62, l2=38). this also leads to an output adjustment, that is, production of good 2 falls to 68 units

36、 and production of good 1 rises to 76 units. and the wage rate is approximately equal to 0.74. q1 q2 l1 l2 ppf ),( 2222 lkqq ),( 1111 lkqq 100 100 1slope 2 1 slope d.calculate the effects of the price change on the income of the specific factors in sectors 1 and 2. with the relative price change fro

37、m p2/p1=2 to p2/p1=1, the price of good 2 has fallen by 50 percent, while the price of good 1 has stayed the same. wages have fallen too, but by less than the fall in p2 (wages fell approximately 25 percent). thus, the real wage relative to p2 actually rises while real wage relative to p1 falls. hen

38、ce, to determine the welfare consequence for workers, the information about their consumption shares of good 1 and good 2 is needed. 3.in the text we examined the impacts of increases in the supply of capital and land. but what if the mobile factor, labor, increases in supply? a analyze the qualitat

39、ive effects of an increase in the supply of labor in the specific factors model, holding the price of both goods constant. for an economy producing two goods, x an y, with labor demands reflected by their marginal revenue product curves, there is an initial wage of w1 and an initial labor allocation

40、 of lx=oxa and ly=oya. when the supply of labor increases, the right boundary of the diagram illustrated below pushed out to oy. the demand for labor in sector y is pulled rightward with the boundary. the new intersection of the labor demand curves shows that labor expands in both sectors, and there

41、fore output of both x and y also expand. the relative expansion of output is ambiguous. wages paid to workers fall. w xx pmpl yy pmpl 1 w 2 w y o y o ab bgraph the effect on the equilibrium for the numerical example in problems 2 and 3, given a relative price of 1, when the labor force expands from

42、100 to 140. with the law of diminishing returns, the new production possibility frontier is more concave and steeper (flatter) at the ends when total labor supply increases. l1 increase to 90 from 62 and l2 increases to 50 from 38. wages decline from 0.74 to 0.60. this new allocation of labor leads

43、to a new output mix of approximately q1=85 and q2=77. q1 q2 l1 l2 ppf ),( 2222 lkqq ),( 1111 lkqq 140 140 100 100 chapter 4 1 in the united states where land is cheap, the ratio of land to labor used in cattle rising is higher than that of land used in wheat growing. but in more crowded countries, w

44、here land is expensive and labor is cheap, it is common to raise cows by using less land and more labor than americans use to grow wheat. can we still say that raising cattle is land intensive compared with farming wheat? why or why not? the definition of cattle growing as land intensive depends on

45、the ratio of land to labor used in production, not on the ratio of land or labor to output. the ratio of land to labor in cattle exceeds the ratio in wheat in the united states, implying cattle is land intensive in the united states. cattle is land intensive in other countries too if the ratio of la

46、nd to labor in cattle production exceeds the ratio in wheat production in that country. the comparison between another country and the united states is less relevant for answering the question. 2 suppose that at current factor prices cloth is produced using 20 hours of labor for each acre of land, a

47、nd food is produced using only 5 hours of labor per acre of land. a.suppose that the economys total resources are 600 hours of labor and 60 acres of land. using a diagram determine the allocation of resources. 5tf lf /tflf /qf)(tf / /qf)(lf atf / alf 20tc lc /tclc /qc)(tc / /qc)(lc atc / alc we can

48、solve this algebraically since l=lc+lf=600 and t=tc+tf=60. the solution is lc=400, tc=20, lf=200 and tf=40. labor land cloth food lc lf tc tf b.now suppose that the labor supply increase first to 800, then 1000, then 1200 hours. using a diagram like figure4-6, trace out the changing allocation of re

49、sources. tion).specializa (complete 0.lf 0,tf 1200,lc 60,tc :1200l 66.67lf 13.33,tf 933.33,lc 46.67,tc :1000l 133.33lf 26.67,tf 666.67,lc 33.33,tc :800l labor land cloth food 0l8000l10000l1200 c.what would happen if the labor supply were to increase even further? at constant factor prices, some labo

50、r would be unused, so factor prices would have to change, or there would be unemployment. 3.“the worlds poorest countries cannot find anything to export. there is no resource that is abundant certainly not capital or land, and in small poor nations not even labor is abundant.” discuss. the gains fro

51、m trade depend on comparative rather than absolute advantage. as to poor countries, what matters is not the absolute abundance of factors, but their relative abundance. poor countries have an abundance of labor relative to capital when compared to more developed countries. 4.the u.s. labor movement

52、which mostly represents blue-collar workers rather than professionals and highly educated workers has traditionally favored limits on imports form less-affluent countries. is this a shortsighted policy of a rational one in view of the interests of union members? how does the answer depend on the mod

53、el of trade? in the ricardos model, labor gains from trade through an increase in its purchasing power. this result does not support labor union demands for limits on imports from less affluent countries. in the immobile factors model labor may gain or lose from trade. purchasing power in terms of o

54、ne good will rise, but in terms of the other good it will decline. the heckscher-ohlin model directly discusses distribution by considering the effects of trade on the owners of factors of production. in the context of this model, unskilled u.s. labor loses from trade since this group represents the

55、 relatively scarce factors in this country. the results from the heckscher-ohlin model support labor union demands for import limits. 5.there is substantial inequality of wage levels between regions within the united states. for example, wages of manufacturing workers in equivalent jobs are about 20

56、 percent lower in the southeast than they are in the far west. which of the explanations of failure of factor price equalization might account for this? how is this case different from the divergence of wages between the united states and mexico (which is geographically closer to both the u.s. south

57、east and the far west than the southeast and far west are to each other)? when we employ factor price equalization, we should pay attention to its conditions: both countries/regions produce both goods; both countries have the same technology of production, and the absence of barriers to trade. inequ

58、ality of wage levels between regions within the united states may caused by some or all of these reasons. actually, the barriers to trade always exist in the real world due to transportation costs. and the trade between u.s. and mexico, by contrast, is subject to legal limits; together with cultural

59、 differences that inhibit the flow of technology, this may explain why the difference in wage rates is so much larger. 6.explain why the leontief paradox and the more recent bowen, leamer, and sveikauskas results reported in the text contradict the factor-proportions theory. the factor proportions t

60、heory states that countries export those goods whose production is intensive in factors with which they are abundantly endowed. one would expect the united states, which has a high capital/labor ratio relative to the rest of the world, to export capital- intensive goods if the heckscher-ohlin theory