中級宏觀經(jīng)濟學講義9

IntermediateMacroeconomics91TheOpenEconomyWhydocountriestradewitheachother?“Nonationwaseverruinedbytrade.”---BenjaminFranklinMorevarieties;higherquality;cheaperprice2TheOpenEconomyMerchandisetradeasa%ofGDP(2005)

MerchandiseTrade(%ofGDP)Highincome43.6Uppermiddleincome66.7Middleincome62.2Lowermiddleincome58.8Lowincome41.13TheOpenEconomy

ArgentinaChinaEthiopiaFranceGermanyHongKongIndiaMexicoU.KU.S.MerchandiseTrade(%ofGDP)37.563.844.945.362.7333.728.25840.121.24TheOpenEconomyTheinternationalflowsofcapital&goodsFactorsaffectingCA(savingsandinvestment)ExchangeratesFactorsaffectingex-rate5InternationalFlowsofK&GoodsCapitalaccount¤taccount6InternationalFlowsofK&Goods(I-S)+NX=0 or KA+CA=0NX≡TB=CA(S-I)≡NFI=-KA7InternationalFlowsofK&GoodsS–I=NX(-KA=CA)IfS–I>0(KA<0)境內(nèi)儲蓄多于境內(nèi)投資部分儲蓄投資到國外(資本凈流出)外國人用這部分資金購買我國商品(商品凈流出)NX>0;TB>0;CA>0;KA<08InternationalFlowsofK&Goods經(jīng)常項目順差：既定時期，一國居民向外國居民的貸出大于借入，從而對外凈資產(chǎn)增加。：本國的凈對外資產(chǎn)余額因此，t時點一國凈對外資產(chǎn)余額是過去經(jīng)常項目盈余或赤字的結(jié)果。

9投資于本國：I或凈對外投資：InternationalFlowsofK&Goods10InternationalFlowsofK&GoodsNX=CA=-KA?我們借來的錢是否可以全被用于購買別國的商品服務?外國人借的人民幣是否可全被用于購買我國的商品服務?No！Wepay/earninterestif(S–I)<>011InternationalFlowsofK&Goods通常情況下,相對于貿(mào)易余額,國外的凈要素支付很小。因此,經(jīng)常項目余額和貿(mào)易余額幾乎相等。Mankiw的假設CA=TB=-KA正是基于此12InternationalFlowsofK&Goods經(jīng)常項目包括：貿(mào)易余額利息/股息其他商品勞務和收入（旅游，工人匯款…）單邊轉(zhuǎn)讓官方轉(zhuǎn)讓其他13InternationalFlowsofK&Goods經(jīng)常項目余額部分構(gòu)成（2005年）（億美元）中國美國日本巴西商品貿(mào)易590-6，6201，321337服務貿(mào)易-97450-379-48要素收入-36-241857-205數(shù)據(jù)來源：IMF2006報告14InternationalFlowsofK&Goods2005ChinaCA:USD160.8billion數(shù)據(jù)來源：中國外匯管理局15InternationalFlowsofK&Goods項

目差額一.經(jīng)常項目1608.183

A.貨物和服務1247.977

a.貨物1341.891

b.服務-93.9139

B.收益106.3514

1.職工報酬15.19648

2.投資收益91.15491

C.經(jīng)常轉(zhuǎn)移253.8547

1.各級政府-1.76234

2.其它部門255.61716InternationalFlowsofK&Goods項

目差額

b.服務-93.9139

1.運輸-130.21

2.旅游75.3693

3.通訊服務-1.18173

4.建筑服務9.73567

5.保險服務-66.5014

6.金融服務-0.14244

7.計算機和信息服務2.17676

8.專有權(quán)利使用費和特許費-51.6385

9.咨詢-8.61408

10.廣告、宣傳3.60521

11.電影、音像-0.20096

12.其它商業(yè)服務74.97029

13.別處未提及的政府服務-1.2817517OtherInterpretations如何評價CA>0(S–I>0)？是好是壞？(S–I)>0國外比國內(nèi)更好的投資機會？量入為出的自律？18兩期國家跨時預算約束

C1>Q1TB赤字C1<Q1TB盈余

無投資。僅選擇消費或儲蓄

19兩期國家跨時預算約束第一期消費大于產(chǎn)出則第二期消費必小于產(chǎn)出若第一期貿(mào)易逆差,則第二期的貿(mào)易必為順差

20兩期國家跨時預算約束

貿(mào)易逆差或經(jīng)常項目逆差本身并不說明好壞，只是一國跨時選擇的結(jié)果?，F(xiàn)在逆差將來必須實現(xiàn)順差，現(xiàn)在順差將來必然享受逆差。21多期國家跨時預算約束

若為有限期，預算約束可得出與兩期模型相同結(jié)論：如果有些時期出現(xiàn)貿(mào)易（經(jīng)常項目）順差，必然有另外的時期是貿(mào)易（經(jīng)常項目）逆差。22但是，對于每個國家，時限可以被假設是無窮的，如何約束？可不可能永遠是逆差或者順差？甚至借新債還舊債無限舉債（PonziScheme）？多期國家跨時預算約束23多期國家跨時預算約束美國會不會是Ponzi？2004：CA赤字0.67萬億占GDP11.67萬億的 5.7%2005：CA赤字0.79萬億占GDP12.5萬億的 6.3%2006：CA赤字0.85萬億占GDP14.98萬億的 5.7%美國的凈外債約占GDP的25％即使CA赤字穩(wěn)定在GDP的5％，2020年凈外債也會>GDP的60％24FactorsaffectingCA

---SmallOpenEconomyWhatmakesacountry“small”?---thescaleoftheeconomyissosmallthatitcannotaffecttheworldpricelevelPricetaker---takeworldrealinterestrate25FactorsaffectingCA

---SmallOpenEconomyr=r*Domestic&foreignbondsareperfectsubstitutesCapitalisperfectlymobile26FactorsaffectingCA

---SmallOpenEconomyModel27FactorsaffectingCA

---SmallOpenEconomyWorldreali-rateandCAKA=-CA=I–Srr*S,ICAISCA(r*)28FactorsaffectingCA

---SmallOpenEconomyI↑rtendsto↑$flowsintillr=r*NFI↓CA↓rS,IISEr*S=II’>S’=SCA=0CA<0

Shocktoinvestment(betterinfrastructure)29FactorsaffectingCA

---SmallOpenEconomyY↓S=(Y–C–G)↓rtendsto↑$flowsintillr=r*NFI↓CA↓rS,IISEr*Hurricane(temporaryshocktoproduction)S=I,CA=0S’<I’=ICA<030FactorsaffectingCA

---SmallOpenEconomyAsYconsistently↑,C↑Swouldnot↑asmuchAlso,investmentmay↑rS,IISEr*Technologicalimprovement(permanentshocktoproduction)temp.shock31FactorsaffectingCA

---SmallOpenEconomyTemporarytradesanctiononIraqTemporaryshocktoTermsofTrade(TOT)toChinaTOT↓Cwouldnot↓muchS↓rtendsto↑$flowsouttillr=r*NFI↓CA↓rS,IISES’<I’=ICA<032FactorsaffectingCA

---SmallOpenEconomyAlargeportionofoilfieldsinIraqweredestroyedduringthewaronTerrorismTOT↓permanentlypeoplewouldadjusttheirCSwouldnotdecreaseasmuch(orevengoesbacktoitsinitiallevel)CAdeficitmaydisappearfinally33FactorsaffectingCA

---SmallOpenEconomyFinancingfortemporaryshocks,adjustingforpersistent(permanent)shocks---IMFCompensatoryFinancingFacility(CFF)Acountrycouldaskforloanswhenitsincomefromexportsisinsufficientandtheinsufficientistemporary.34FactorsaffectingCA

---SmallOpenEconomyInfluenceofhomeexpansionaryfiscalpoliciesG↑orT↓S↓Iunchanged(S-I)↓NFI↓&NX↓(CA<0)rS,IISEI’<S’=SCA<035FactorsaffectingCA

---SmallOpenEconomyInaSOE,anexpansionaryfiscalpolicy(G↑orT↓)squeezesouttheNXHigherbudgetdeficitathomeleadstohighertradedeficit(currentaccountdeficit)---TheTwinDeficits36FactorsaffectingCA

---SmallOpenEconomyInfluenceofforeignfiscalpolicies(large)