投资学第六版第7章课后答案.doc

1.  Becauseveryfewsecuritieswillexhibitperfectlypositivecorrelation,diversificationwilltendtoreduceportfoliorisk. Thus,foranygivenlevelofexpectedreturn,onewouldexpectthatportfolioswillexhibitlowerrisk(liefurthertothewestinthefeasibleset)thanindividualportfolios(whichwillthereforelietotheeastinthefeasibleset).2.  Diversifiedportfoliosaremoreefficientthanindividualsecurities. Thatis,ivenlevelsofriskand/paredwithindividualsecurities. Diagrammatically,individualsecuritieswilllieintheeasternportionofthefeasibleset. Hencetheyaredominatedbydiversifiedportfolios,whichlieinthenorthwesternportionofthefeasibleset,.  (and,hence,stockprices)orporations,,paniestoexperienceadownturninearnings. paniesmaybemoreseverelyaffectedthanothers,nevertheless,panies'panies. Whenautosalesarestrong(weak),thedemandforsteelgenerallyrises(falls). paniesinbothindustrieswouldriseandfallatroughlythesametimeandthismovementwouldlikelybeanticipatedbytheearlierriseandfalloftheirstocks'panieswhosestockswouldbeexpectedtohavealowcovariancearebanksandgoldminingfirms. Risinginterestratesandpoorbusinessconditionsgenerallyproducedecliningbankearnings. Atthesametime,old,whichincreasesthepriceofgoldand,therefore,theearningsofgoldmi