第1題Inthesimpleregressionmodely=b0+b1x+u,thexandyarerespectivelycalled_____.AtheexplanatoryvariableandtheexplainedvariableBthedependentvariableandtheindependentvariableCtheresponsevariableandthecontrolvariableDtheregressandandtheregressor第2題Thezeroconditionalmeanassumptionimplies____.AzeroeffectofxonyBzerocorrelationbetweenxandyCzerocorrelationbetweenxanduDzeroeffectofuony第3題ThesumoftheOLSresidualsiszero.Thus,thesampleaverageoftheOLSresidualsiszeroaswell.____.AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第4題ThesamplecovariancebetweentheregressorsandtheOLSresidualsiszero.____.AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第5題TheOLSregressionlinealwaysgoesthroughthemeanofthesample.____.AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第6題Whenthinkingabouthowwelloursampleregressionlinefitsoursampledata,wecancomputethefractionofthetotalsumofsquares()thatisexplainedbythemodel,andcallthistheR-squaredoftheregression.____.AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第1題Itisverydifficulttodrawceterisparibusconclusionsabouthowxaffectsy:thezeroconditionalmeanassumptionisoftenunrealistic.____AThisstatementshowstheadvantageofthesimpleregressionmodel.BThisstatementshowsthedrawbackofthesimpleregressionmodel.CThisstatementisfalse.第2題Themultipleregressionmodelisstillthemostwidelyusedvehicleforempiricalanalysisineconomicsandothersocialsciences.______AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第3題Whichofthefollowingistrue?______AThepowerofsimpleregressionanalysisisthatitprovidestheceterisparibusinterpretationeventhoughthedatahavenotbeencollectedinaceterisparibusfashion.BThepowerofmultipleregressionanalysisisthatitprovidestheceterisparibusinterpretationwheneverthedatahavenotbeencollectedinaceterisparibusfashion.CTheweaknessofmultipleregressionanalysisisthatitdoesnotprovidetheceterisparibusinterpretationeventhoughthedatahavebeencollectedinaceterisparibusfashion.DThepowerofmultipleregressionanalysisisthatitprovidestheceterisparibusinterpretationeventhoughthedatahavenotbeencollectedinaceterisparibusfashion.第4題BecauseR2willusuallyincreasewiththenumberofindependentvariables,itisnotagoodwaytocompareacrossmodels._____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第5題ThefactorthatshoulddeterminewhetheranexplanatoryvariablebelongsinamodeliswhethertheexplanatoryvariablesignificantlyincreasesR2oftheregression.______AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第6題Ifanexplanatoryvariableisanexactlinearcombinationoftheotherexplanatoryvariables,thenthemodelsuffersfromperfectcollinearity,anditcannotbeestimatedbyOLS._____.AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第7題Whichofthefollowingistrue?_____AIncludingoneormoreirrelevantvariablesinamultipleregressionmodelaffectstheunbiasednessoftheOLSestimators.BIncludingoneormoreirrelevantvariablesinamultipleregressionmodeldoesnotaffecttheunbiasednessoftheOLSestimators.CIncludingoneormoreirrelevantvariablesinamultipleregressionmodeldoesnotaffecttheefficiencyoftheOLSestimators.DIncludingoneormoreirrelevantvariablesinamultipleregressionmodel,oroverspecifyingthemodel,doesnotaffectthegoodness-of-fitoftheOLSestimators第8題Alargervarianceoftheestimatormeansamorepreciseestimator,andthistranslatesintolargerconfidenceintervalsandlessaccuratehypothesestests._____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第9題Whichofthefollowingistrue?_____APerfectcorrelationbetweentwoormoreoftheindependentvariablesiscalledmulticollinearity.BLowcorrelationbetweentwoormoreoftheindependentvariablesiscalledmulticollinearity.CHighbutnotperfectcorrelationbetweentwoormoreoftheindependentvariablesiscalledmulticollinearity.DNon-zerocorrelationbetweentwoormoreoftheindependentvariablesiscalledmulticollinearity.Chapter3Homework第1題Whichofthefollowingstatementsistrue?____AMultipleregressionanalysisislessamenabletoceterisparibusanalysisbecauseitallowsustoexplicitlycontrolformanyotherfactorswhichsimultaneouslyaffectthedependentvariable.BMultipleregressionanalysisismoreamenabletoceterisparibusanalysisbecauseitdoesnotallowustoexplicitlycontrolformanyotherfactorswhichsimultaneouslyaffectthedependentvariable.CMultipleregressionanalysisismoreamenabletoceterisparibusanalysisbecauseitallowsustoexplicitlycontrolformanyotherfactorswhichsimultaneouslyaffectthedependentvariable.DMultipleregressionanalysisismoreamenabletoceterisparibusanalysisbecauseitallowsustoimplicitlycontrolformanyotherfactorswhichsimultaneouslyaffectthedependentvariable.第2題TheFstatisticisoftenusefulfortestingexclusionofagroupofvariableswhenthevariablesinthegrouparehighlycorrelated.____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.Chapter4Homework第1題Itisimportanttoknowtheasymptoticpropertiesofestimatorsandteststatistics.Thesepropertiesarenotdefinedforaparticularsamplesize;theyareinsteaddefinedasthesamplesizegrowswithoutbound.____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第2題Eventhoughtheyiarenotfromanormaldistribution,wecanconcludethattheOLSestimatorsareapproximatelynormallydistributed,atleastinlargesamplesizes.____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.Chapter5Homework第1題Whenusingnaturallogsweshouldbecarefulabouttheunitsofmeasurementofvariablesappearinginlogarithmicformbecausetheslopecoefficientsarevarianttorescalings.____AThisstatementisnecessarilytrue.BThisstatementisnecessarilyfalse.CThisstatementisambiguous.第2題Theissueofwhetherornottocontrolforcertainfactorsisnotalwaysclear-cut.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter6Homework第1題Qualitativefactorsoftencomeintheformofbinaryinformation.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.第2題Insomecases,theordinalvariabletakesontoomanyvaluessothatadummyvariablecannotbeincludedforeachvalue.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter7Homework第1題Homoskedasticityfailswhenthevarianceoftheunobservableschangesacrossdifferentsegmentsofthepopulation,whicharedeterminedbythedifferentvaluesoftheexplanatoryvariables.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter8Homework第1題Inthespecialcasethattheomittedvariableisafunctionofanexplanatoryvariableinthemodel,themodelsuffersfromfunctionalformmisspecification.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter9Homework第1題Ifcertainconditionsinhistoryhadbeendifferent,wewouldgenerallyhaveobtainedadifferentrealizationforthestochasticprocess,andthisiswhywethinkoftimeseriesdataastheoutcomeofrandomvariables.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.第2題Explanatoryvariablesthatarestrictlyexogenouscannotreacttowhathashappenedtoyinthepast.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.第3題Astationarytimeseriesprocessisonewhoseprobabilitydistributionsarestableovertimeinthefollowingsense:ifwetakeanycollectionofrandomvariablesinthesequenceandthenshiftthatsequenceaheadhtimeperiods,thejointprobabilitydistributionmustremainunchanged.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter10Homework第1題Anindependentlypooledcrosssectiondiffersfromasinglerandomsampleinthatsamplingfromthepopulationatdifferentpointsintimelikelyleadstoobservationsthatarenotidenticallydistributed.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.第2題Apaneldataset,whilehavingbothacross-sectionalandatimeseriesdimension,differsinsomeimportantrespectsfromanindependentlypooledcrosssection.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.第3題Anaturalexperimentoccurswhensomeexogenousevent—oftenachangeingovernmentpolicy—changestheenvironmentinwhichindividuals,families,firms,orcitiesoperate.____AThisstatementistrue.BThisstatementisfalse.CThisstatementisambiguous.Chapter11Homework第1題TheIVmeth