斯蒂芬D威廉森宏观经济学第三版第十五章Stephen D. Williamson2七S Macroeconomics,Third Edition 15

Chapter15Money,InflationandBankingChapter15TopicsAlternativeformsofmoney.Moneyandtheabsenceofdoublecoincidenceofwants.Thecausesandeffectsoflong-runinflation.Financialintermediationandbanking.2AlternativeFormsofMoneyCommoditymoneyCirculatingprivatebanknotesCommodity-backedpapercurrencyFiatmoneyTransactionsdepositsatbanks3TheDouble-CoincidenceProblemandtheRoleofMoneyBarterexchangeisdifficultinhighly-developed,specializedeconomies.Economicexchangerequiressearchcosts,andthesecostsarehighwheneconomicagentsarespecializedinconsumptionandproduction,andcanonlytradeagoodorserviceforanothergoodorservice.Searchcostsarereduceddramaticallyifeveryoneacceptsmoneyinexchangeforgoodsandservices.4Figure15.1AnAbsence-of-Double-CoincidenceEconomy5Figure15.2Good1asaCommodityMoneyintheAbsence-of-Double-CoincidenceEconomy6Figure15.3FiatMoneyintheAbsence-of-Double-CoincidenceEconomy7TheEffectsofLong-RunInflationUsethemonetaryintertemporalmodelfromChapter10.Showthatmoneyisnotsuperneutral–highermoneygrowthcauseshigherinflation,whichaffectsrealeconomicvariables.Anincreaseinthemoneygrowthrateincreasestheinflationrateandthenominalinterestrate,andreducesemploymentandoutput.8Figure15.4ScatterplotoftheInflationRatevs.theGrowthRateinM0fortheUnitedStates,1960–20239Equation15.1Assumethatthecentralbankcausesthemoneysupplytogrowataconstantrate.10Equation15.2Inequilibrium,moneysupplyequalsmoneydemand.11Equation15.3Moneysupplyalsoequalsmoneydemandinthefutureperiod.12Equation15.4Combinetheprevioustwoequations.13Equation15.5Theconsumer’sintertemporalmarginalcondition.14Equation15.6Marginalconditionreflectingtheconsumer’stradeoffbetweencurrentleisureandfutureconsumption:15Equation15.7Marginalconditionreflectingtheconsumer’stradeoffbetweencurrentleisureandcurrentconsumption:16Figure15.5TheLong-RunEffectsofanIncreaseintheMoneyGrowthRate17TheFriedmanRuleInflationcausesaninefficiency,inthatitdistortsintertemporaldecisions.TheFriedmanruleisaprescriptionformonetarygrowththateliminatestheinefficiencycausedbyinflation.TheFriedmanrulespecifiesthatthemoneystockgrowataratethatmakesthenominalinterestratezero.Inpractice,nocentralbankappearstohaveadoptedaFriedmanruletoguidemonetarypolicy.18Equation15.9Paretooptimalityrequiresthat19Equation15.10Inacompetitiveequilibrium,20Equation15.11Also,inacompetitiveequilibrium,21PropertiesofAssetsRateofreturnRiskMaturityLiquidity22DefiningCharacteristicsofFinancialIntermediariesBorrowfromonegroupofeconomicagentsandlendtoanother.Well-diversifiedwithrespecttobothassetsandliabilities.Transformassets.Processinformation.23TheDiamond-DybvigBankingModelThreeperiods,0,1,and2.Twotypesofconsumers:early(consumeinperiod1)andlate(consumeinperiod2)Efficienteconomicarrangementisforconsumerstosetupabankinordertosharerisk.Giventhebank’sdepositcontract,thebankisopentoarun,whichisabadequilibrium.24Figure15.6TheUtilityFunctionForaConsumerintheDiamond–DybvigModel25Figure15.7ThePreferencesofaDiamond–DybvigConsumer26Equation15.12Themarginalrateofsubstitutionofearlyconsumptionforlateconsumptionis27Equation15.13Firstconstraintthatadepositcontractmustsatisfyis28Equation15.14Secondconstraintthatadepositcontractmustsatis