成本收益分析课件

成本收益分析

Cost-BenefitAnalysisPublicFinanceMcGraw-Hill/Irwin©2005TheMcGraw-HillCompanies,Inc.,AllRightsReserved.IntroductionCost-benefitanalysisisasetofpracticalproceduresforguidingpublicexpendituredecisions.FutureValue（终值）：

PresentDollarsintotheFutureSupposeyouinvest$100todayinthebank...Attheendofyear1,itisworth(1+.05)x$100,or$105Attheendofyear2,itisworth(1+.05)x$105,or$110.25Theinterestcompoundsovertime,thatis,theinterestisalsoearninginterest.PresentValue（现值）:

FutureDollarsintothePresentSupposesomeonepromisestopayyou$100oneyearfromnow.Whatisthemaximumamountyoushouldbewillingtopaytodayforsuchapromise?PresentValue:

FutureDollarsintothePresentThepresentvalueofafutureamountofmoneyisthemaximumamountyouwouldbewillingtopaytodayfortherighttoreceivethemoneyinthefuture.PresentValue:

FutureDollarsintothePresentDefineR=amounttobereceivedinfuturer=rateofreturnoninvestmentT=yearsofinvestmentThepresentvalue(PV)oftheinvestmentis:PresentValue:

FutureDollarsintothePresentPresentvalueisanenormouslyimportantconceptA$1,000,000payment20yearsfromnowisonlyworthtoday:$376,889ifr=.05$148,644ifr=.10PrivateSectorProjectEvaluation

私人部门的项目评估Supposetherearetwoprojects,XandY.Eachentailscertainbenefitsandcosts,denotedasBX,CX,BY,andCY.Needtoask:Istheprojectadmissible（可行）?Istheprojectpreferable（最好）?PrivateSectorProjectEvaluationDefine:BenefitsfromprojectiattimetCostsfromprojectiattimetThenthepresentvalueofprojectiis:PrivateSectorProjectEvaluationThepresentvaluecriteria

（现值标准）forprojectevaluationarethat:Aprojectisadmissibleonlyifitspresentvalueispositive.Whentwoprojectsaremutuallyexclusive（二选一的）,thepreferredprojectistheonewiththehighestpresentvalue.PrivateSectorProjectEvaluationTable1showstwodifferentprojects(R&DorAdvertising).Thediscountrateplaysakeyroleindecidingwhatprojecttochoose,becausethecashinflowsoccuratdifferenttimes.Thelowerthediscountrate,themorevaluabletheback-loadedproject.PrivateSectorProjectEvaluationSeveralothercriteriaareoftenusedforprojectevaluation,butcangivemisleadinganswersInternalrateofreturn（内部收益率）Benefit-costratio（收益－成本比率）PrivateSectorProjectEvaluationTheinternalrateofreturn,ρ,isdefinedastheρthatsolvestheequation:TheIRRisthediscountratethatwouldmakethepresentvalueoftheprojectequaltozero.Admissibleifρ>r.Theflawedanalysiswouldchooseanadmissibleprojectwiththehigherinternalrateofreturn,ignoringscale.X项目现在投入100，一年后收入110Y项目现在投入1000，一年后收入1080假定企业按6％的利率借贷X项目赚了4美元，Y项目赚了20美元PrivateSectorProjectEvaluationAdmissibilityusingthebenefit-costratiorequires:Thisratioisvirtuallyuselessforcomparingacrossadmissibleprojects,however.Ratiocanbemanipulatedbycountingbenefitsas“negativecosts”andvice-versa.案例分析方案1：建造垃圾场B=2.5亿美