International-Financial-Management---Bekaert-2e---Solutions---Ch13.doc
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Chapter13:
InternationalCapitalMarketEquilibrium
Chapter 13
InternationalCapitalMarketEquilibrium
QUESTIONS
1.IsthevolatilityofthedollarreturntoaninvestmentintheJapaneseequitymarketthesumofthevolatilityoftheJapaneseequitymarketreturninyenplusthevolatilityofyen/dollarexchangeratechanges?
Whyorwhynot?
Answer:
Itisnot.EventhoughthedollarreturnoninvestinginJapaneseequityisapproximatelytheyenreturnontheJapaneseequitymarketplustherateofchangeinthedollar/yenexchangerate,thevolatilityofthissumisnotthesumofthevolatilities.Intuitively,becausetheequityriskandcurrencyriskarenothighlycorrelated,partofthevolatilityoftheindividualcomponentsisdiversifiedaway.Technically,thevarianceofthedollarreturnscanbewrittenasfollows:
Var[r(t+1,¥)+s(t+1)]=Var[r(t+1,¥)]+Var[s(t+1)]+2ρVol[r(t+1,¥)]Vol[s(t+1)]
wherer(t+1,¥)istheyen-denominatedequityreturn,s(t+1)istherateofchangeinthedollar/yenexchangerate,andρisthecorrelationbetweentheyenequityreturnanddollar/yenexchangeratechanges.Becausevolatility,Vol,isthesquarerootofthevariance,weknowthatthevolatilityofthedollarreturnonaJapaneseequityinvestmentis
Vol[r(t+1,¥)+s(t+1)]={Vol[r(t+1,¥)]2+Vol[s(t+1)]2+
2ρVol[r(t+1,¥)]Vol[s(t+1)]}0.5
Clearly,onlywhenthecorrelationisexactly1willtheright-handsidehavetheform
(A2+2AB+B2)0.5=[(A+B)2]0.5=(A+B)
Hence,onlythenwillthevolatilityofthesumbethesumofthevolatilities.Whenthereisperfectcorrelation,thereisnonaturaldiversificationadvantagetohavingexposuretotwosourcesofrisk.However,aslongasρ<1,thetotalvolatilityofthedollarreturntoinvestingintheJapaneseequitymarketwillbelessthanthesumofthetwovolatilities.
2.WhyisthevarianceofaportfolioofinternationallydiversifiedstockslikelytobelowerthanthevarianceofaportfolioofU.S.stocks?
Answer:
Withinternationalstocks,theinvestorcandiversifyawayU.S.-specificsourcesofvolatility(e.g.U.S.–specificbusinesscyclemovements,changesinU.S.monetarypolicy,changesinU.S.interestrates,etc.).Technically,thevarianceofanequallyweightedportfolioconvergestotheaveragecovariancebetweenthesestockswhenthenumberofstocksgetsverylarge.TheaveragecovarianceamongU.S.stocksishigherthantheaveragecovarianceamongasetofU.S.andinternationalstocks.
3.HowcanyouincreasetheSharperatioofaportfolio?
Whattypeofstockswouldyouhavetoaddtoitinordertodoso?
Answer:
ToincreasetheSharperatioonyourportfolio,youmustaddstocksthatincreasetheexpectedreturnonyourportfolioand/orreducethevolatilityoftheportfolio(forinstance,becausethestocksexhibitlowcorrelationwiththeportfolioyoualreadyhave).Onewaytothinkoftheproblemistocomputethefollowinghurdlerate,
Hurdlerate=
Inthisequationrfistheriskfreerate,ρisthecorrelationbetweentheportfolioyouhaveandthestockyouwanttoaddtotheportfolio,E[r]andVol[r]aretheexpectedreturnandvolatilityoftheportfolioyouareholding,andVol[r*]isthevolatilityofthestockyouwanttoadd.ThehurdlerateishigherwhentheexistingportfoliohasahighSharperatio,thestockyouareaddingismorevolatile,orthereishighcorrelationbetweenthereturnontheportfolioandthereturnonthestockyouareaddingtotheportfolio.
4.WhyisthehurdlerateinSection13.2lowerforJapanthanforCanada?
ShouldU.S.investorsstillinvestinCanada?
Answer:
FromtheformulaintheanswertoQuestion3,weseethatthetwomaindriversofthehurdleratesarethecorrelationsbetweenCanadianandU.S.returnsandbetweenJapaneseandU.S.returns(reportedinExhibit13.6),andthevolatilitiesofCanadianandJapanesereturns(reportedinExhibit13.1).Themostimportantnumberisthecorrelation.OftheG7countries,theCanadianreturnshavethehighestcorrelationwithU.S.returns,whereastheJapanesereturnshavethelowestcorrelation.ItisthisdifferencethatmakesJapanhavethelowesthurdlerateandCanadathehighest.WhetherU.S.investorsshouldstillinvestinCanadadependsontheiropportunityset.ThehurdlerateforCanada,reportedinExhibit13.7,suggeststhateveniftheexpectedreturnonCanadianstockisonlyabitlowerthanthatoftheU.S.,itisstillavaluableinvestmentthatincreasestheSharperatio.However,iftheU.S.investorcaninvestinJapanesesecuritiesfirst,theCanadianhurdleratewillincreaseconsiderably,becausetheU.S.-JapandiversifiedportfoliohasahighSharperatio.Inthatcase,itmaynotbeoptimaltogolongCanadiansecuritiesunlessyoureallybelievetheCanadianstockmarketwillhaveanexpectedreturnh