中级宏观经济学讲义9

1IntermediateMacroeconomics92TheOpenEconomyWhydocountriestradewitheachother?“Nonationwaseverruinedbytrade.”---BenjaminFranklinMorevarieties;higherquality;cheaperprice3TheOpenEconomyMerchandisetradeasa%ofGDP(2005)MerchandiseTrade(%ofGDP)Highincome43.6Uppermiddleincome66.7Middleincome62.2Lowermiddleincome58.8Lowincome41.14TheOpenEconomyArgentinaChinaEthiopiaFranceGermanyHongKongIndiaMexicoU.KU.S.MerchandiseTrade(%ofGDP)37.563.844.945.362.7333.728.25840.121.25TheOpenEconomyTheinternationalflowsofcapital&goodsFactorsaffectingCA(savingsandinvestment)ExchangeratesFactorsaffectingex-rate6InternationalFlowsofK&GoodsCapitalaccount¤taccountNXGICY0NXIGCY0NXISNXIS7InternationalFlowsofK&Goods(I-S)+NX=0orKA+CA=0NX≡TB=CA(S-I)≡NFI=-KA8InternationalFlowsofK&GoodsS–I=NX(-KA=CA)IfS–I0(KA0)境内储蓄多于境内投资部分储蓄投资到国外(资本净流出)外国人用这部分资金购买我国商品(商品净流出)NX0;TB0;CA0;KA09InternationalFlowsofK&Goods经常项目顺差：既定时期，一国居民向外国居民的贷出大于借入，从而对外净资产增加。：本国的净对外资产余额因此，t时点一国净对外资产余额是过去经常项目盈余或赤字的结果。**012ttBBCACACA*B*1*BBISCA10投资于本国：I或净对外投资：**1()BB**1()SIBBInternationalFlowsofK&Goods11InternationalFlowsofK&GoodsNX=CA=-KA?我们借来的钱是否可以全被用于购买别国的商品服务?外国人借的人民币是否可全被用于购买我国的商品服务?No！Wepay/earninterestif(S–I)012InternationalFlowsofK&Goods通常情况下,相对于贸易余额,国外的净要素支付很小。因此,经常项目余额和贸易余额几乎相等。Mankiw的假设CA=TB=-KA正是基于此*1rBTBCA13InternationalFlowsofK&Goods经常项目包括：贸易余额利息/股息其他商品劳务和收入（旅游，工人汇款…）单边转让官方转让其他14InternationalFlowsofK&Goods经常项目余额部分构成（2005年）（亿美元）中国美国日本巴西商品贸易590-6，6201，321337服务贸易-97450-379-48要素收入-36-241857-205数据来源：IMF2006报告15InternationalFlowsofK&Goods2005ChinaCA:USD160.8billion77%7%16%Goods&ServicesIncome&ProfitCurrentTransfers数据来源：中国外汇管理局16InternationalFlowsofK&Goods项目差额一.经常项目1608.183A.货物和服务1247.977a.货物1341.891b.服务-93.9139B.收益106.35141.职工报酬15.196482.投资收益91.15491C.经常转移253.85471.各级政府-1.762342.其它部门255.61717InternationalFlowsofK&Goods项目差额b.服务-93.91391.运输-130.212.旅游75.36933.通讯服务-1.181734.建筑服务9.735675.保险服务-66.50146.金融服务-0.142447.计算机和信息服务2.176768.专有权利使用费和特许费-51.63859.咨询-8.6140810.广告、宣传3.6052111.电影、音像-0.2009612.其它商业服务74.9702913.别处未提及的政府服务-1.2817518OtherInterpretations如何评价CA0(S–I0)？是好是坏？(S–I)0国外比国内更好的投资机会？量入为出的自律？19两期国家跨时预算约束22,CQ11,CQ1Q2QC1Q1TB赤字C1Q1TB盈余无投资。仅选择消费或储蓄20两期国家跨时预算约束第一期消费大于产出则第二期消费必小于产出若第一期贸易逆差,则第二期的贸易必为顺差0121rTBTB021CACA21两期国家跨时预算约束贸易逆差或经常项目逆差本身并不说明好坏，只是一国跨时选择的结果。现在逆差将来必须实现顺差，现在顺差将来必然享受逆差。22多期国家跨时预算约束若为有限期，预算约束可得出与两期模型相同结论：如果有些时期出现贸易（经常项目）顺差，必然有另外的时期是贸易（经常项目）逆差。23但是，对于每个国家，时限可以被假设是无穷的，如何约束？可不可能永远是逆差或者顺差？甚至借新债还旧债无限举债（PonziScheme）？10(1)DrD多期国家跨时预算约束2210(1)(1)DrDrD24多期国家跨时预算约束美国会不会是Ponzi？2004：CA赤字0.67万亿占GDP11.67万亿的5.7%2005：CA赤字0.79万亿占GDP12.5万亿的6.3%2006：CA赤字0.85万亿占GDP14.98万亿的5.7%美国的净外债约占GDP的25％即使CA赤字稳定在GDP的5％，2020年净外债也会GDP的60％25FactorsaffectingCA---SmallOpenEconomyWhatmakesacountry“small”?---thescaleoftheeconomyissosmallthatitcannotaffecttheworldpricelevelPricetaker---takeworldrealinterestrate26FactorsaffectingCA---SmallOpenEconomyr=r*Domestic&foreignbondsareperfectsubstitutesCapitalisperfectlymobile27FactorsaffectingCA---SmallOpenEconomyModelISNFINX*)()(rIGTYCYNX28FactorsaffectingCA---SmallOpenEconomy1.Worldreali-rateandCAKA=-CA=I–Srr*S,ICAISCA(r*)29FactorsaffectingCA---SmallOpenEconomyI↑rtendsto↑$flowsintillr=r*NFI↓CA↓rS,IISEr*S=II’S’=SCA=0CA0Shocktoinvestment(betterinfrastructure)30FactorsaffectingCA---SmallOpenEconomyY↓S=(Y–C–G)↓rtendsto↑$flowsintillr=r*NFI↓CA↓rS,IISEr*Hurricane(temporaryshocktoproduction)S=I,CA=0S’I’=ICA031FactorsaffectingCA---SmallOpenEconomyAsYconsistently↑,C↑Swouldnot↑asmuchAlso,investmentmay↑rS,IISEr*Technologicalimprovement(permanentshocktoproduction)temp.shock32FactorsaffectingCA---SmallOpenEconomyTemporarytradesanctiononIraqTemporaryshocktoTermsofTrade(TOT)toChinaTOT↓Cwouldnot↓muchS↓rtendsto↑$flowsouttillr=r*NFI↓CA↓rS,IISES’I’=ICA033FactorsaffectingCA---SmallOpenEconomyAlargeportionofoilfieldsinIraqweredestroyedduringthewaronTerrorismTOT↓permanentlypeoplewouldadjusttheirCSwouldnotdecreaseasmuch(orevengoesbacktoitsinitiallevel)CAdeficitmaydisappearfinally34FactorsaffectingCA---SmallOpenEconomyFinancingfortemporaryshocks,adjustingforpersistent(permanent)shocks---IMFCompensatoryFinancingFacility(CFF)Acountrycouldaskforloanswhenitsincomefromexportsisinsufficientandtheinsufficientistemporary.35FactorsaffectingCA---SmallOpenEconomyInfluenceofhomeexpansionaryfiscalpoliciesG↑orT↓S↓Iunchanged(S-I)↓NFI↓&NX↓(CA0)rS,IISEI’S’=SCA036FactorsaffectingCA---SmallOpenEconomyInaSOE,anexpansionaryfiscalpolicy(G↑orT↓)squeezesouttheNXHigherbudgetdeficitathomeleadstohighertradedeficit(currentaccountdeficit)---TheTwinDeficits37FactorsaffectingCA---SmallOpenEconomyInfluenceofforeignfiscalpolicies(large)G(f)↑orT(f)↓S(f)↓r(f)↑r*↑$flowsoutoftheSOENFI↑&CA↑rS,IISr*S’I’CA038LargeCountryCanbeconsideredasthecasebetweenSOEandclosedeconomyr*willbepartiallydriventowardthedirectionthatrchanges39LargeCountryE.g.Drought(temporaryproductionshock)Y↓S↓rtendsto↑$flowsin(NFI↓)r*↑CA↓,butsmallerthanSOErS,IISES’I’=ICA0SS’I’ICA040LargeCoun