曼昆宏观经济学最新英文版参考答案第26章

Chapter26ProblemsandApplications1.a.ThebondofaneasternEuropeangovernmentwouldpayahigherinterestratethanthebondoftheU.S.governmentbecausetherewouldbeagreaterriskofdefault.b.Abondthatrepaystheprincipalin2025wouldpayahigherinterestratethanabondthatrepaystheprincipalin2005becauseithasalongertermtomaturity,sothereismorerisktotheprincipal.c.AbondfromasoftwarecompanyyouruninyourgaragewouldpayahigherinterestratethanabondfromCoca-Colabecauseyoursoftwarecompanyhasmorecreditrisk.d.AbondissuedbythefederalgovernmentwouldpayahigherinterestratethanabondissuedbyNewYorkStatebecauseaninvestordoesnothavetopayfederalincometaxonthebondfromNewYorkstate.2.Thestockmarketdoeshaveasocialpurpose.Firmsobtainfundsforinvestmentbyissuingnewstock.Peoplearemorelikelytobuythatstockbecausethereareorganizedstockmarkets,sopeopleknowthattheycanselltheirstockiftheywantto.3.WhentheRussiangovernmentdefaultedonitsdebt,investorsperceivedahigherchanceofdefault(thantheyhadbefore)onsimilarbondssoldbyotherdevelopingcountries.Thus,thesupplyofloanablefundsshiftedtotheleft,asshowninFigure1.Theresultwasanincreaseintheinterestrate.Figure14.Companiesencouragetheiremployeestoholdstockinthecompanybecauseitgivestheemployeestheincentivetocareaboutthefirm’sprofits,notjusttheirownsalary.Then,ifemployeesseewasteorseeareasinwhichthefirmcanimprove,theywilltakeactionsthatbenefitthecompanybecausetheyknowthevalueoftheirstockwillriseasaresult.Italsogivesemployeesanadditionalincentivetoworkhard,knowingthatifthefirmdoeswell,theywillprofit.Butfromanemployee’spointofview,owningstockinthecompanyforwhichsheorheworkscanberisky.Theemployee’swagesorsalaryisalreadytiedtohowwellthefirmperforms.Ifthefirmhastrouble,theemployeecouldbelaidofforhaveherorhissalaryreduced.Iftheemployeeownsstockinthefirm,thenthereisadoublewhammytheemployeeisunemployedorgetsalowersalaryandthevalueofthestockfallsaswell.Soowningstockinyourowncompanyisaveryriskyproposition.Mostemployeeswouldbebetteroffdiversifyingowningstockorbondsinothercompaniessotheirfortuneswouldnotdependsomuchonthefirmforwhichtheywork.5.Toamacroeconomist,savingoccurswhenaperson’sincomeexceedshisconsumption,whileinvestmentoccurswhenapersonorfirmpurchasesnewcapital,suchasahouseorbusinessequipment.a.Whenyourfamilytakesoutamortgageandbuysanewhouse,thatisinvestmentbecauseitisapurchaseofnewcapital.b.Whenyouuseyour$200paychecktobuystockinAT&T,thatissavingbecauseyourincomeof$200isnotbeingspentonconsumptiongoods.c.Whenyourroommateearns$100anddepositsitinheraccountatabank,thatissavingbecausethemoneyisnotspentonconsumptiongoods.d.Whenyouborrow$1,000fromabanktobuyacartouseinyourpizza-deliverybusiness,thatisinvestmentbecausethecarisacapitalgood.6.GiventhatY=8,T=1.5,Sprivate=0.5=Y−T−C,Spublic=0.2=T−G.BecauseSprivate=Y−T−C,thenrearranginggivesC=Y−T−Sprivate=8−1.5−0.5=6.BecauseSpublic=T−G,thenrearranginggivesG=T−Spublic=1.5−0.2=1.3.BecauseS=nationalsaving=Sprivate+Spublic=0.5+0.2=0.7.Finally,becauseI=investment=S,I=0.7.7.a.Ifinterestratesincrease,thecostsofborrowingmoneytobuildthefactorybecomehigher,sothereturnsfrombuildingthenewplantmaynotbesufficienttocoverthecosts.Thus,higherinterestratesmakeitlesslikelythatIntelwillbuildthenewfactory.b.EvenifIntelusesitsownfundstofinancethefactory,theriseininterestratesstillmatters.Thereisanopportunitycostontheuseofthefunds.Insteadofinvestinginthefactory,Intelcouldinvestthemoneyinthebondmarkettoearnthehigherinterestrateavailablethere.Intelwillcompareitspotentialreturnsfrombuildingthefactorytothepotentialreturnsfromthebondmarket.Ifinterestratesrise,sothatbondmarketreturnsrise,Intelisagainlesslikelytoinvestinthefactory.Figure28.a.Figure2illustratestheeffectofthe$20billionincreaseingovernmentborrowing.Initially,thesupplyofloanablefundsiscurveS1,theequilibriumrealinterestrateisi1,andthequantityofloanablefundsisL1.Theincreaseingovernmentborrowingby$20billionreducesthesupplyofloanablefundsateachinterestrateby$20billion,sothenewsupplycurve,S2,isshownbyashifttotheleftofS1byexactly$20billion.Asaresultoftheshift,thenewequilibriumrealinterestrateisi2.Theinterestratehasincreasedasaresultoftheincreaseingovernmentborrowing.b.Becausetheinterestratehasincreased,investmentandnationalsavingdeclineandprivatesavingincreases.Theincreaseingovernmentborrowingreducespublicsaving.Fromthefigureyoucanseethattotalloanablefunds(andthusbothinvestmentandnationalsaving)declinebylessthan$20billion,whilepublicsavingdeclinesby$20billionandprivatesavingrisesbylessthan$20billion.c.Themoreelasticisthesupplyofloanablefunds,theflatterthesupplycurvewouldbe,sotheinterestratewouldrisebylessandthusnationalsavingwouldfallbyless,asFigure3shows.Figure3Figure4d.Themoreelasticthedemandforloanablefunds,theflatterthedemandcurvewouldbe,sotheinterestratewouldrisebylessandthusnationalsavingwouldfallbymore,asFigure4shows.e.Ifhouseholdsbelievethatgreatergovernmentborrowingtodayimplieshighertaxestopayoffthegovernmentdebtinthefuture,thenpeoplewillsavemoresotheycanpaythehigherfuturetaxes.Thus,privatesavingwillincrease,aswillthesupplyofloanablefunds.Thiswilloffsetthereducti