计量经济学伍德里奇第六版考试题库及答案（英文版）

Chapter1

1.Econometricsisthebranchofeconomicsthat.

a.studiesthebehaviorofindividualeconomicagentsinmakingeconomicdecisions

b.developsandusesstatisticalmethodsforestimatingeconomicrelationships

c.dealswiththeperformance,structure,behavior,anddecision-makingofaneconomyasawhole

d.appliesmathematicalmethodstorepresenteconomictheoriesandsolveeconomicproblems.

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:WhatisEconometrics?

BUSPROG:

Feedback:Econometricsisthebranchofeconomicsthatdevelopsandusesstatisticalmethodsfor

estimatingeconomicrelationships.

2.Nonexperimentaldataiscalled.

a.cross-sectionaldata

b.timeseriesdata

c.observationaldata

d.paneldata

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:WhatisEconometrics?

BUSPROG:

Feedback:

3.Whichofthefollowingistrueofexperimentaldata?

a.Experimentaldataarecollectedinlaboratoryenvironmentsinthenaturalsciences.

b.Experimentaldatacannotbecollectedinacontrolledenvironment.

c.Experimentaldataissometimescalledobservationaldata.

d.Experimentaldataissometimescalledretrospectivedata.

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:WhatisEconometrics?

BUSPROG:

Feedback:

4.Anempiricalanalysisreliesontotestatheory.

a.commonsense

b.ethicalconsiderations

c.data

d.customsandconventions

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:StepsinEmpiricalEconomicAnalysis

BUSPROG:

Feedback:Anempiricalanalysisreliesondatatotestatheory.

5.Theterminaneconometricmodelisusuallyreferredtoasthe.

a.errorterm

b.parameter

c.hypothesis

d.dependentvariable

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:StepsinEmpiricalEconomicAnalysis

BUSPROG:

Feedback:Thetermuinaneconometricmodeliscalledtheerrortermordisturbanceterm.

6.Theparametersofaneconometricmodel.

a.includeallunobservedfactorsaffectingthevariablebeingstudied

b.describethestrengthoftherelationshipbetweenthevariableunderstudyandthefactorsaffectingit

c.refertotheexplanatoryvariablesincludedinthemodel

d.refertothepredictionsthatcanbemadeusingthemodel

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:StepsinEmpiricalEconomicAnalysis

BUSPROG:

Feedback:Theparametersofaneconometricmodeldescribethedirectionandstrengthofthe

relationshipbetweenthevariableunderstudyandthefactorsaffectingit.

7.Whichofthefollowingisthefirststepinempiricaleconomicanalysis?

a.Collectionofdata

b.Statementofhypotheses

c.Specificationofaneconometricmodel

d.Testingofhypotheses

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:StepsinEmpiricalEconomicAnalysis

BUSPROG:

Feedback:Thefirststepinempiricaleconomicanalysisisthespecificationoftheeconometricmodel.

8.Adatasetthatconsistsofasampleofindividuals,households,firms,cities,states,countries,ora

varietyofotherunits,takenatagivenpointintime,iscalleda(n).

a.cross-sectionaldataset

b.longitudinaldataset

c.timeseriesdataset

d.experimentaldataset

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheStructureofEconomicData

BUSPROG:

Feedback:Adatasetthatconsistsofasampleofindividuals,households,firms,cities,states,countries,

oravarietyofotherunits,takenatagivenpointintime,iscalledacross-sectionaldataset.

9.Dataontheincomeoflawgraduatescollectedatdifferenttimesduringthesameyearis.

a.paneldata

b.experimentaldata

c.timeseriesdata

d.cross-sectionaldata

Answer:d

Difficulty:Easy

Bloom's:Application

A-Head:TheStructureofEconomicData

BUSPROG:Analytic

Feedback:Adatasetthatconsistsofasampleofindividuals,households,firms,cities,states,countries,

oravarietyofotherunits,takenatagivenpointintime,iscalledacross-sectionaldataset.Therefore,

dataontheincomeoflawgraduatesonaparticularyearareexamplesofcross-sectionaldata.

10.Adatasetthatconsistsofobservationsonavariableorseveralvariablesovertimeiscalleda

dataset.

a.binary

b.cross-sectional

c.timeseries

d.experimental

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheStructureofEconomicData

BUSPROG:

Feedback:Atime-seriesdatasetconsistsofobservationsonavariableorseveralvariablesovertime.

11.Whichofthefollowingisanexampleoftimeseriesdata?

a.Dataontheunemploymentratesindifferentpartsofacountryduringayear.

b.Dataontheconsumptionofwheatby200householdsduringayear.

c.Dataonthegrossdomesticproductofacountryoveraperiodof10years.

d.Dataonthenumberofvacanciesinvariousdepartmentsofanorganizationonaparticularmonth.

Answer:c

Difficulty:Easy

Bloom's:Application

A-Head:TheStructureofEconomicData

BUSPROG:Analytic

Feedback:Atime-seriesdatasetconsistsofobservationsonavariableorseveralvariablesover

time.Therefore,dataonthegrossdomesticproductofacountryoveraperiodof10yearsisanexample

oftimeseriesdata.

12.Whichofthefollowingreferstopaneldata?

a.Dataontheunemploymentrateinacountryovera5-yearperiod

b.Dataonthebirthrate,deathrateandpopulationgrowthrateindevelopingcountriesovera10-year

period.

c.Dataontheincomeof5membersofafamilyonaparticularyear.

d.Dataonthepriceofacompany'sshareduringayear.

Answer:b

Difficulty:Easy

Bloom's:Application

A-Head:TheStructureofEconomicData

BUSPROG:Analytic

Feedback:Apaneldatasetconsistsofatimeseriesforeachcross-sectionalmemberinthedataset.

Therefore,dataonthebirthrate,deathrateandinfantmortalityrateindevelopingcountriesovera

10-yearperiodreferstopaneldata.

13.Whichofthefollowingisadifferencebetweenpanelandpooledcross-sectionaldata?

a.Apaneldatasetconsistsofdataondifferentcross-sectionalunitsoveragivenperiodoftimewhilea

pooleddatasetconsistsofdataonthesamecross-sectionalunitsoveragivenperiodoftime.

b.Apaneldatasetconsistsofdataonthesamecross-sectionalunitsoveragivenperiodoftimewhilea

pooleddatasetconsistsofdataondifferentcross-sectionalunitsoveragivenperiodoftime

c.Apaneldataconsistsofdataonasinglevariablemeasuredatagivenpointintimewhileapooled

datasetconsistsofdataonthesamecross-sectionalunitsoveragivenperiodoftime.

d.Apaneldatasetconsistsofdataonasinglevariablemeasuredatagivenpointintimewhileapooled

datasetconsistsofdataonmorethanonevariableatagivenpointintime.

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheStructureofEconomicData

BUSPROG:

Feedback:Apaneldatasetconsistsofdataonthesamecross-sectionalunitsoveragivenperiodoftime

whileapooleddatasetconsistsofdataonthesamecross-sectionalunitsoveragivenperiodoftime.

14.hasacausaleffecton.

a.Income;unemployment

b.Height;health

c.Income;consumption

d.Age;wage

Answer:c

Difficulty:Moderate

Bloom's:Application

A-Head:CausalityandtheNotionofCeterisParibusinEconometricAnalysis

BUSPROG:Analytic

Feedback:Incomehasacausaleffectonconsumptionbecauseanincreaseinincomeleadstoan

increaseinconsumption.

15.Whichofthefollowingistrue?

a.Avariablehasacausaleffectonanothervariableifbothvariablesincreaseordecrease

simultaneously.

b.Thenotionof"ceterisparibus'playsanimportantroleincausalanalysis.

c.Difficultyininferringcausalitydisappearswhenstudyingdataatfairlyhighlevelsofaggregation.

d.Theproblemofinferringcausalityarisesifexperimentaldataisusedforanalysis.

Answer:b

Difficulty:Moderate

Bloom's:Knowledge

A-Head:CausalityandtheNotionofCeterisParibusinEconometricAnalysis

BUSPROG:

Feedback:Thenotionof'ceterisparibus'playsanimportantroleincausalanalysis.

16.Experimentaldataaresometimescalledretrospectivedata.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:WhatisEconometrics?

BUSPROG:

Feedback:Nonexperimentaldataaresometimescalledretrospectivedata.

17.Aneconomicmodelconsistsofmathematicalequationsthatdescribevariousrelationshipsbetween

economicvariables.

Answer:True

Difficulty:Easy

Bloom's:Knowledge

A-Head:StepsinEmpiricalEconomicAnalysis

BUSPROG:

Feedback:Aneconomicmodelconsistsofmathematicalequationsthatdescribevariousrelationships

betweeneconomicvariables.

18.Across-sectionaldatasetconsistsofobservationsonavariableorseveralvariablesovertime.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheStructureofEconomicData

BUSPROG:

Feedback:Atimeseriesdatasetconsistsofobservationsonavariableorseveralvariablesover

time.

19.Atimeseriesdataisalsocalledalongitudinaldataset.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheStructureofEconomicData

BUSPROG:

Feedback:Atimeseriesdataisalsocalledalongitudinaldataset.

20.Thenotionofceterisparibusmeans"otherfactorsbeingequal.”

Answer:True

Difficulty:Easy

Bloom's:Knowledge

A-Head:CausalityandtheNotionofCeterisParibusinEconometricAnalysis

BUSPROG:

Feedback:Thenotionofceterisparibusmeans“otherfactorsbeingequal."

Chapter2

1.Adependentvariableisalsoknownasa(n).

a.explanatoryvariable

b.controlvariable

c.predictorvariable

d.responsevariable

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:DefinitionoftheSimpleRegressionModel

BUSPROG:

Feedback:Adependentvariableisknownasaresponsevariable.

2.Ifachangeinvariablexcausesachangeinvariabley,variablexiscalledthe.

a.dependentvariable

b.explainedvariable

c.explanatoryvariable

d.responsevariable

Answer:c

Difficulty:Easy

Bloom's:Comprehension

A-Head:DefinitionoftheSimpleRegressionModel

BUSPROG:

Feedback:Ifachangeinvariablexcausesachangeinvariabley,variablexiscalledtheindependent

variableortheexplanatoryvariable.

3.Intheequationy=p0+ptx+u,p0isthe.

a.dependentvariable

b.independentvariable

c.slopeparameter

d.interceptparameter

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:DefinitionoftheSimpleRegressionModel

BUSPROG:

Feedback:Intheequationy=p0+ptx+u,p0istheinterceptparameter.

4.Intheequationy=0。+pxx+u,whatistheestimatedvalueofp0?

a.y-匹天

b.y+piX

£-i(Xi一幻(yi-力

d.Silixy

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:DerivingtheOrdinaryLeastSquaresEstimates

BUSPROG:

Feedback:Theestimatedvalueofp0isy—匹x.

5.Intheequationc=p0++u,cdenotesconsumptionandidenotesincome.Whatistheresidual

th

forthe5observationifc5=$500andQ=$475?

a.$975

b.$300

c.$25

d.$50

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:DerivingtheOrdinaryLeastSquaresEstimates

BUSPROG:

Feedback:Theformulaforcalculatingtheresidualfortheithobservationis=y,—yj.Inthiscase,the

residualisuj=c5-=$500-$475=$25.

6.Whatdoestheequationy=Po+雷xdenoteiftheregressionequationisy=po+PiXi+u?

a.Theexplainedsumofsquares

b.Thetotalsumofsquares

c.Thesampleregressionfunction

d.Thepopulationregressionfunction

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:DerivingtheOrdinaryLeastSquaresEstimates

BUSPROG:

Feedback:Theequationy=Po4-田xdenotesthesampleregressionfunctionofthegivenregression

model.

7.Considerthefollowingregressionmodel:y=p0+PiXi+u.Whichofthefollowingisapropertyof

OrdinaryLeastSquare(OLS)estimatesofthismodelandtheirassociatedstatistics?

a.Thesum,andthereforethesampleaverageoftheOLSresiduals,ispositive.

b.ThesumoftheOLSresidualsisnegative.

c.ThesamplecovariancebetweentheregressorsandtheOLSresidualsispositive.

d.Thepoint(x,y)alwaysliesontheOLSregressionline.

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:

Feedback:AnimportantpropertyoftheOLSestimatesisthatthepoint(x,y)alwaysliesontheOLS

regressionline.Inotherwords,ifx=x,thepredictedvalueofyisy.

8.Theexplainedsumofsquaresfortheregressionfunction,y,=p0+0iXi+ulzisdefinedas.

a-S^Cvi-y)2

b.一夕)2

c.E陶Ut

d.EkiQi)2

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:

Feedback:TheexplainedsumofsquaresisdefinedasE仁式%—y)2

9.Ifthetotalsumofsquares(SST)inaregressionequationis81,andtheresidualsumofsquares(SSR)is

25,whatistheexplainedsumofsquares(SSE)?

a.64

b.56

c.32

d.18

Answer:b

Difficulty:Moderate

Bloom's:Application

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:Analytic

Feedback:Totalsumofsquares(SST)isgivenbythesumofexplainedsumofsquares(SSE)andresidual

sumofsquares(SSR).Therefore,inthiscase,SSE=81-25=56.

10.Iftheresidualsumofsquares(SSR)inaregressionanalysisis66andthetotalsumofsquares(SST)is

equalto90,whatisthevalueofthecoefficientofdetermination?

a.0.73

b.0.55

c.0.27

d.1.2

Answer:c

Difficulty:Moderate

Bloom's:Application

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:Analytic

SSR

Feedback:TheformulaforcalculatingthecoefficientofdeterminationisR2=1——.Inthiscase,

R2=1-—=0.27

90

11.Whichofthefollowingisanonlinearregressionmodel?

a.y=Po+Pix1/2+u

b.logy=p0+Pilogx+u

c.y=1/(po+Pix)+u

d.y=Po+Pix+u

Answer:c

Difficulty:Moderate

Bloom's:Comprehension

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:

Feedback:Aregressionmodelisnonlineariftheequationisnonlinearintheparameters.Inthiscase,

y=l/(po+Pix)+uisnonlinearasitisnonlinearinitsparameters.

12.WhichofthefollowingisassumedforestablishingtheunbiasednessofOrdinaryLeastSquare(OLS)

estimates?

a.Theerrortermhasanexpectedvalueof1givenanyvalueoftheexplanatoryvariable.

b.Theregressionequationislinearintheexplainedandexplanatoryvariables.

c.Thesampleoutcomesontheexplanatoryvariableareallthesamevalue.

d.Theerrortermhasthesamevariancegivenanyvalueoftheexplanatoryvariable.

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:ExpectedValuesandVariancesoftheOLSEstimators

BUSPROG:

Feedback:Theerroruhasthesamevariancegivenanyvalueoftheexplanatoryvariable.

13.Theerrorterminaregressionequationissaidtoexhibithomoskedastictyif.

a.ithaszeroconditionalmean

b.ithasthesamevarianceforallvaluesoftheexplanatoryvariable.

c.ithasthesamevalueforallvaluesoftheexplanatoryvariable

d.iftheerrortermhasavalueofonegivenanyvalueoftheexplanatoryvariable.

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:ExpectedValuesandVariancesoftheOLSEstimators

BUSPROG:

Feedback:Theerrorterminaregressionequationissaidtoexhibithomoskedastictyifithasthesame

varianceforallvaluesoftheexplanatoryvariable.

14.Intheregressionofyonx,theerrortermexhibitsheteroskedasticityif.

a.ithasaconstantvariance

b.Var(y|x)isafunctionofx

c.xisafunctionofy

d.yisafunctionofx

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:ExpectedValuesandVariancesoftheOLSEstimators

BUSPROG:

Feedback:HeteroskedasticityispresentwheneverVar(y|x)isafunctionofxbecauseVar(u|x)=

Var(y|x).

15.Whatistheestimatedvalueoftheslopeparameterwhentheregressionequation,y=p0+PiXi+

upassesthroughtheorigin?

b.E之式%—y)

器

器凸2

d.£上式%—y)2

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:RegressionthroughtheOriginandRegressiononaConstant

BUSPROG:

Feedback:Theestimatedvalueoftheslopeparameterwhentheregressionequationpassesthroughthe

16.Anaturalmeasureoftheassociationbetweentworandomvariablesisthecorrelationcoefficient.

Answer:True

Difficulty:Easy

Bloom's:Knowledge

A-Head:DefinitionoftheSimpleRegressionModel

BUSPROG:

Feedback:Anaturalmeasureoftheassociationbetweentworandomvariablesisthecorrelation

coefficient.

17.ThesamplecovariancebetweentheregressorsandtheOrdinaryLeastSquare(OLS)residualsis

alwayspositive.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:

Feedback:ThesamplecovariancebetweentheregressorsandtheOrdinaryLeastSquare(OLS)residuals

iszero.

18.R2istheratiooftheexplainedvariationcomparedtothetotalvariation.

Answer:True

Difficulty:Easy

Bloom's:Knowledge

A-Head:PropertiesofOLSonAnySampleofData

BUSPROG:

Feedback:ThesamplecovariancebetweentheregressorsandtheOrdinaryLeastSquare(OLS)residuals

iszero.

19.Therearen-1degreesoffreedominOrdinaryLeastSquareresiduals.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:ExpectedValuesandVariancesoftheOLSEstimators

BUSPROG:

Feedback:Therearen-2degreesoffreedominOrdinaryLeastSquareresiduals.

20.Thevarianceoftheslopeestimatorincreasesastheerrorvariancedecreases.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:ExpectedValuesandVariancesoftheOLSEstimators

BUSPROG:

Feedback:Thevarianceoftheslopeestimatorincreasesastheerrorvarianceincreases.

Chapter3

xis

1.Intheequation,y=p0+4-p22+u,p2a(n).

a.independentvariable

b.dependentvariable

c.slopeparameter

d.interceptparameter

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:MotivationforMultipleRegression

BUSPROG:

】xs

Feedback:Intheequation,y=p04-BiX+p22+u,02>aslopeparameter.

xXu

2.Considerthefollowingregressionequation:y=Bi+B2i+B22+-Whatdoespiimply?

a.measurestheceterisparibuseffectofXionx2.

b.measurestheceterisparibuseffectofyonx1.

c.Bimeasurestheceterisparibuseffectofy.

d.01measurestheceterisparibuseffectofxxonu.

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:MotivationforMultipleRegression

BUSPROG:

Feedback:仇measurestheceterisparibuseffectofXiony.

3.Iftheexplainedsumofsquaresis35andthetotalsumofsquaresis49,whatistheresidualsumof

squares?

a.10

b.12

c.18

d.14

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:MechanicsandInterpretationofOrdinaryLeastSquares

BUSPROG:Analytic

Feedback:Theresidualsumofsquaresisobtainedbysubtractingtheexplainedsumofsquaresfromthe

totalsumofsquares,or49-35=14.

4.WhichofthefollowingistrueofR2?

a.R2isalsocalledthestandarderrorofregression.

b.AlowR2indicatesthattheOrdinaryLeastSquareslinefitsthedatawell.

c.R2usuallydecreaseswithanincreaseinthenumberofindependentvariablesinaregression.

d.R2showswhatpercentageofthetotalvariationinthedependentvariable,Y,isexplainedbythe

explanatoryvariables.

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:MechanicsandInterpretationofOrdinaryLeastSquares

BUSPROG:

Feedback:R2showswhatpercentageofthetotalvariationinYisexplainedbytheexplanatoryvariables.

5.ThevalueofR2always.

a.liesbelow0

b.liesabove1

c.liesbetween0and1

d.liesbetween1and1.5

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:MechanicsandInterpretationofOrdinaryLeastSquares

BUSPROG:

Feedback:Bydefinition,thevalueofR2alwaysliesbetween0and1.

6.Ifanindependentvariableinamultiplelinearregressionmodelisanexactlinearcombinationof

otherindependentvariables,themodelsuffersfromtheproblemof.

a.perfectcollinearity

b.homoskedasticity

c.heteroskedasticty

d.omittedvariablebias

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:Ifanindependentvariableinamultiplelinearregressionmodelisanexactlinearcombination

ofotherindependentvariables,themodelsuffersfromtheproblemofperfectcollinearity.

7.Theassumptionthattherearenoexactlinearrelationshipsamongtheindependentvariablesina

multiplelinearregressionmodelfailsif,wherenisthesamplesizeandkisthenumberof

parameters.

a.n>2

b.n=k+l

c.n>k

d.n<k+l

Answer:d

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:Theassumptionofnoperfectcollinearityamongindependentvariablesfailsifn<k+l.

8.Exclusionofarelevantvariablefromamultiplelinearregressionmodelleadstotheproblemof

a.misspecificationofthemodel

b.multicollinearity

c.perfectcollinearity

d.homoskedasticity

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:Exclusionofarelevantvariablefromamultiplelinearregressionmodelleadstotheproblem

ofmisspecificationofthemodel.

9.Supposethevariablex2hasbeenomittedfromthefollowingregressionequation,y=p04-Six1+

B2X2+u.B1istheestimatorobtainedwhenX2isomittedfromtheequation.Thebiasinpxispositive

if.

a.02>0andx1andx2arepositivelycorrelated

b.02<0ar,dx1andx2arepositivelycorrelated

c.02>0andx1andx2arenegativelycorrelated

d.p2=0andx1andx2arenegativelycorrelated

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:WhenthevariableX2isomittedfromtheregression,thebiasinispositiveifp2>0andx

1andx2arepositivelycorrelated.

10.Supposethevariablex2hasbeenomittedfromthefollowingregressionequation,y=p04-4-

B2X2+u.01istheestimatorobtainedwhenX2isomittedfromtheequation.Thebiasinis

negativeif.

a.p2>0andx1andx2arepositivelycorrelated

b.”<0andx1andx2arepositivelycorrelated

c.02=0andXiandx2arenegativelycorrelated

d.阮=0andx1andx2arenegativelycorrelated

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:WhenthevariableX2isomittedfromtheregression,thebiasinisnegativeifp2<0and

x1andx2arepositivelycorrelated.

11.Supposethevariablex2hasbeenomittedfromthefollowingregressionequation,y=p0+BiX1+

B2X2+u.Biistheestimatorobtainedwhenx2isomittedfromtheequation.If)>Pi,issaid

to.

a.haveanupwardbias

b.haveadownwardbias

c.beunbiased

d.bebiasedtowardzero

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:WhenthevariableX2isomittedfromthefollowingregressionequation,y=Bo+PiXx4-

p2^2+u,,p1hasanupwardbiasifE(pt)>Pi.

12.High(butnotperfect)correlationbetweentwoormoreindependentvariablesiscalled.

a.heteroskedasticty

b.homoskedasticty

c.multicollinearity

d.micronumerosity

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheVarianceoftheOLSEstimators

BUSPROG:

Feedback:High,butnotperfect,correlationbetweentwoormoreindependentvariablesiscalled

multicollinearity.

13.Thetermreferstotheproblemofsmallsamplesize.

a.micronumerosity

b.multicollinearity

c.homoskedasticity

d.heteroskedasticity

Answer:a

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheVarianceoftheOLSEstimators

BUSPROG:

Feedback:Thetermmicronumerosityreferstotheproblemofsmallsamplesize.

14.Findthedegreesoffreedominaregressionmodelthathas10observationsand7independent

variables.

a.17

b.2

c.3

d.4

Answer:b

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheVarianceoftheOLSEstimators

BUSPROG:Analytic

Feedback:Thedegreesoffreedominaregressionmodeliscomputedbysubtractingthenumberof

parametersfromthenumberofobservationsinaregressionmodel.Since,thenumberofparametersis

onemorethanthenumberofindependentvariables,thedegreesoffreedominthiscaseis10-(7+1)=

2.

15.TheGauss-Markovtheoremwillnotholdif.

a.theerrortermhasthesamevariancegivenanyvaluesoftheexplanatoryvariables

b.theerrortermhasanexpectedvalueofzerogivenanyvaluesoftheindependentvariables

c.theindependentvariableshaveexactlinearrelationshipsamongthem

d.theregressionmodelreliesonthemethodofrandomsamplingforcollectionofdata

Answer:c

Difficulty:Easy

Bloom's:Knowledge

A-Head:EfficiencyofOLS:TheGauss-MarkovTheorem

BUSPROG:

Feedback:TheGauss-Markovtheoremwillnotholdiftheindependentvariableshaveexactlinear

relationshipsamongthem.

16.Theterm"linear"inamultiplelinearregressionmodelmeansthattheequationislinearin

parameters.

Answer:True

Difficulty:Easy

Bloom's:Knowledge

A-Head:MotivationforMultipleRegression

BUSPROG:

Feedback:Theterm“linear“inamultiplelinearregressionmodelmeansthattheequationislinearin

parameters.

17.Thekeyassumptionforthegeneralmultipleregressionmodelisthatallfactorsintheunobserved

errortermbecorrelatedwiththeexplanatoryvariables.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:MotivationforMultipleRegression

BUSPROG:

Feedback:Thekeyassumptionofthegeneralmultipleregressionmodelisthatallfactorsinthe

unobservederrortermbeuncorrelatedwiththeexplanatoryvariables.

18.Thecoefficientofdetermination(R2)decreaseswhenanindependentvariableisaddedtoamultiple

regressionmodel.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:MechanicsandInterpretationofOrdinaryLeastSquares

BUSPROG:

Feedback:Thecoefficientofdetermination(R2)neverdecreaseswhenanindependentvariableisadded

toamultipleregressionmodel.

19.Anexplanatoryvariableissaidtobeexogenousifitiscorrelatedwiththeerrorterm.

Answer:False

Difficulty:Easy

Bloom's:Knowledge

A-Head:TheExpectedValueoftheOLSEstimators

BUSPROG:

Feedback:Anexplanatoryvariableissaidtobeendogenousifitiscorrelatedwiththeerrorterm.

20.Alargererrorvariancemakesitdifficultto