lOMoARcPSD|27111031 Chapter 8 - Lecture notes 8 Statistical Analysis For Economics And Finance (Baruch College CUNY) Studocu is not sponsored or endorsed by any college or university Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 I nt r oduc t i ont oEc onome t r i c s ,3e( St oc k) Chapt er8 Nonl i ne arRegr es s i onFunc t i ons 8. 1 Mul t i pl eChoi c e 1)I nnonl i ne armode l s ,t hee xpe c t e dc hangei nt hede pe nde ntvar i abl ef orac hangei noneoft he e xpl ana t or yvar i abl e si sgi ve nby A)△Y=f ( X1+X1,X2, . . .Xk ) . B)△Y=f ( X1+△X1,X2+△X2, . . . ,Xk +△Xk ) -f ( X1,X2, . . . Xk ) . C)△Y=f ( X1+△X1,X2, . . . ,Xk ) -f ( X1,X2, . . . Xk ) . D)△Y=f ( X1+X1,X2, . . . ,Xk ) -f ( X1,X2, . . . Xk ) . Ans we r :C 2)Thei nt e r pr e t a t i onoft hes l opec oe ffic i e nti nt hemode lYi=β n( Xi )+uii sasf ol l ows : 0+β 1l A)a1% c hangei nXi sas s oc i a t e dwi t haβ hangei nY. 1% c B)a1% c hangei nXi sas s oc i a t e dwi t hac hangei nYof0. 01β 1. C)ac hangei nXbyoneuni ti sas s oc i a t e dwi t haβ 1 0 0 % c h a ngei nY. 1 D)ac hangei nXbyoneuni ti sas s oc i a t e dwi t haβ hangei nY. 1c Ans we r :B 3)Thei nt e r pr e t a t i onoft hes l opec oe ffic i e nti nt hemode ll n( Yi )=β sasf ol l ows : 0+β 1Xi+uii A)a1% c hangei nXi sas s oc i a t e dwi t haβ hangei nY. 1% c B)ac hangei nXbyoneuni ti sas s oc i a t e dwi t ha100β hangei nY. 1% c C)a1% c hangei nXi sas s oc i a t e dwi t hac hangei nYof0. 01β . 1 D)ac hangei nXbyoneuni ti sas s oc i a t e dwi t haβ c h a n g e i n Y. 1 Ans we r :B 4)Thei nt e r pr e t a t i onoft hes l opec oe ffic i e nti nt hemode ll n( Yi )=β n( Xi ) +uii sasf ol l ows : 0+β 1l A)a1% c hangei nXi sas s oc i a t e dwi t haβ % c h a n g e i n Y . 1 B)ac hangei nXbyoneuni ti sas s oc i a t e dwi t haβ hangei nY. 1c C)ac hangei nXbyoneuni ti sas s oc i a t e dwi t ha100β % c h angei nY. 1 D)a1% c hangei nXi sas s oc i a t e dwi t hac hangei nYof0. 01β 1. Ans we r :A 1 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 5)I nt hec as eofr e gr e s s i onwi t hi nt e r a c t i ons ,t hec oe ffic i e ntofabi nar yvar i abl es houl dbei nt e r pr e t e das f ol l ows : A)t he r ear er e al l ypr obl e msi ni nt e r pr e t i ngt he s e ,s i nc et hel n( 0)i snotde fine d. B)f ort hec as eofi nt e r a c t e dr e gr e s s or s ,t hebi nar yvar i abl ec oe ffic i e ntr e pr e s e nt st hevar i ousi nt e r c e pt sf or t hec as ewhe nt hebi nar yvar i abl ee qual sone . C)fir s ts e tal le xpl ana t or yvar i abl e st oone ,wi t ht hee x c e pt i onoft hebi nar yvar i abl e s .The nal l ow f ore ac h oft hebi nar yvar i abl e st ot a keont heval ueofones e que nt i al l y .Ther e s ul t i ngpr e di c t e dval uei ndi c a t e st he e ffe c toft hebi nar yvar i abl e . D)fir s tc omput et hee xpe c t e dval ue sofYf ore ac hpos s i bl ec as ede s c r i be dbyt hes e tofbi nar yvar i abl e s . Ne xtc ompar et he s ee xpe c t e dval ue s .Eac hc oe ffic i e ntc ant he nbee xpr e s s e de i t he rasane xpe c t e dval ueor ast hedi ffe r e nc ebe t we e nt woormor ee xpe c t e dval ue s . Ans we r :D 6)Thef ol l owi ngi nt e r ac t i onsbe t we e nbi nar yandc ont i nuousvar i abl e sar epos s i bl e ,wi t ht hee x c e pt i onof A)Yi=β Xi×Di )+ui . 0+β 1Xi+β 2Di+β 3( B)Yi=β Xi×Di )+ui . 0+β 1Xi+β 2( C)Yi=( β + D ) + β X + u . 0 i 1i i D)Yi=β . 0+β 1Xi+β 2Di+ui Ans we r :C 7)Ane xampl eoft hei nt e r ac t i ont e r m be t we e nt woi nde pe nde nt ,c ont i nuousvar i abl e si s A)Yi=β + β X + β D + β ( X × D ) + u . 0 1i 2i 3 i i i B)Yi=β . 0+β 1X1i+β 2X2i+ui C)Yi=β D1i×D2i )+ui . 0+β 1D1i+β 2D2i+β 3( D)Yi=β + β X + β X + β ( X × X ) + u . 0 1 1i 2 2i 3 1i 2i i Ans we r :D 8)I nc l udi ngani nt e r ac t i ont e r m be t we e nt woi nde pe nde ntvar i abl e s ,X1andX2,al l owsf ort hef ol l owi ng e x c e pt : A)t hei nt e r a c t i ont e r ml e t st hee ffe c tonYofac hangei nX1de pe ndont heval ueofX2. B)t hei nt e r a c t i ont e r mc oe ffic i e nti st hee ffe c tofauni ti nc r e as ei nX1andX2aboveandbe yondt hes um oft hei ndi vi duale ffe c t sofauni ti nc r e as ei nt het wovar i abl e sal one . C)t hei nt e r a c t i ont e r mc oe ffic i e nti st hee ffe c tofauni ti nc r e as ei n . D)t hei nt e r a c t i ont e r ml e t st hee ffe c tonYofac hangei nX2de pe ndont heval ueofX1. Ans we r :C 9)Anonl i ne arf unc t i on A)make sl i t t l es e ns e ,be c aus evar i abl e si nt her e a lwor l dar er e l a t e dl i ne ar l y . B)c anbeade qua t e l yde s c r i be dbyas t r ai ghtl i nebe t we e nt hede pe nde ntvar i abl eandoneoft he e xpl ana t or yvar i abl e s . C)i sac onc e ptt ha tonl yappl i e st ot hec as eofas i ngl eort woe xpl ana t or yvar i abl e ss i nc eyouc annotdr a w al i nei nf ourdi me ns i ons . D)i saf unc t i onwi t has l opet ha ti snotc ons t ant . Ans we r :C 2 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 10)Ane xampl eofaquadr a t i cr e gr e s s i onmode li s 2 A)Yi=β + β X + β Y + u . 0 1 2 i B)Yi=β + β l n ( X ) + u . 0 1 i 2 C)Yi=β + β X + β X . 0 1 2 +ui D) =β . 0+β 1X+ui Ans we r :C 2,t =607. 3+3. 85I nc o me–0. 0423I nc o me hef ol l owi ng 11)( Re qui r e sCal c ul us )I nt hee qua t i on i nc omel e ve lr e s ul t si nt hemaxi mum t e s ts c or e A)607. 3. B)91. 02. C)45. 50. D)c annotbede t e r mi ne dwi t houtapl otoft heda t a . Ans we r :C 12)Tode c i dewhe t he rYi=β n( Yi )=β st heda t abe t t e r ,youc annotc ons ul t 0+β 1X+uiorl 0+β 1X+uifit 2 t her e gr e s s i onR be c aus e A)l n( Y)ma ybene ga t i vef or0<Y<1. B)t heTSSar enotme as ur e di nt hes ameuni t sbe t we e nt het womode l s . C)t hes l openol onge ri ndi c a t e st hee ffe c tofauni tc hangeofXonYi nt hel ogl i ne armode l . 2 D)t her e gr e s s i onR c anbegr e a t e rt hanonei nt hes e c ondmode l . Ans we r :B 13)Youha vee s t i ma t e dt hef ol l owi nge qua t i on: 2, =607. 3+3. 85I nc o me–0. 0423I nc o me whe r eTe s t Sc o r ei st hea ve r a geoft her e adi ngandma t hs c or e sont heSt anf or d9s t andar di ze dt e s t t h admi ni s t e r e dt o5 gr ades t ude nt si n420Cal i f or ni as c hooldi s t r i c t si n1998and1999.I nc o mei st he a ve r a geannualpe rc api t ai nc omei nt hes c hooldi s t r i c t ,me as ur e di nt hous andsof1998dol l ar s .The e qua t i on A)s ugge s t sapos i t i ver e l a t i ons hi pbe t we e nt e s ts c or e sandi nc omef ormos toft hes ampl e . B)i spos i t i veunt i laval ueofI nc o meof610. 81. C)doe snotmakemuc hs e ns es i nc et hes quar eofi nc omei se nt e r e d. D)s ugge s t sapos i t i ver e l a t i ons hi pbe t we e nt e s ts c or e sandi nc omef oral loft hes ampl e . Ans we r :A 3 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 14)Apol ynomi alr e gr e s s i onmode li ss pe c i fie das : A)Yi=β ∙ ∙+β X +ui . 0+β 1Xi+β 2X +∙ r B)Yi=β ∙ ∙+β Xi+ui . 0+β 1Xi+β Xi+∙ C)Yi=β ∙ ∙+β Y +ui . 0+β 1Xi+β 2Y +∙ r D)Yi=β X1i×X2i )+ui . 0+β 1X1i+β 2X2+β 3( Ans we r :A 15)Fort hepol ynomi alr e gr e s s i onmode l , A)youne e dne we s t i ma t i ont e c hni que ss i nc et heOLSas s umpt i onsdonotappl yanyl onge r . B)t het e c hni que sf ore s t i ma t i onandi nf e r e nc ede ve l ope df ormul t i pl er e gr e s s i onc anbeappl i e d. C)youc ans t i l lus eOLSe s t i ma t i ont e c hni que s ,butt het s t a t i s t i c sdonotha veanas ympt ot i cnor mal di s t r i but i on. D)t hec r i t i c alval ue sf r om t henor maldi s t r i but i onha vet obec hange dt o1. 962,1. 963,e t c . Ans we r :B 16)Tot e s twhe t he rornott hepopul a t i onr e gr e s s i onf unc t i oni sl i ne arr a t he rt hanapol ynomi alofor de rr , 2 A)c he c kwhe t he rt her e gr e s s i onR f ort hepol ynomi alr e gr e s s i oni shi ghe rt hant ha toft hel i ne ar r e gr e s s i on. B)c ompar et heTSSf r om bot hr e gr e s s i ons . C)l ooka tt hepa t t e r noft hec oe ffic i e nt s :i ft he yc hangef r om pos i t i vet one ga t i vet opos i t i ve ,e t c . ,t he nt he pol ynomi alr e gr e s s i ons houl dbeus e d. et het e s tof( r 1)r e s t r i c t i onsus i ngt heFs t a t i s t i c . D)us Ans we r :D 17)Thebe s twa yt oi nt e r pr e tpol ynomi alr e gr e s s i onsi st o A)t akeade r i va t i veofYwi t hr e s pe c tt ot her e l e vantX. B)pl ott hee s t i ma t e dr e gr e s s i onf unc t i onandt oc al c ul a t et hee s t i ma t e de ffe c tonYas s oc i a t e dwi t ha c hangei nXf oroneormor eval ue sofX. C)l ooka tt het s t a t i s t i c sf ort her e l e vantc oe ffic i e nt s . D)anal yzet hes t andar de r r orofe s t i ma t e de ffe c t . Ans we r :B 18)Thee xpone nt i alf unc t i on A)i st hei nve r s eoft hena t ur all ogar i t hm f unc t i on. B)doe snotpl a yani mpor t antr ol ei nmode l i ngnonl i ne arr e gr e s s i onf unc t i onsi ne c onome t r i c s . x C)c anbewr i t t e nase xp( e) . x,whe D)i se r eei s3. 1415…. Ans we r :A 4 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 19)Thef ol l owi ngar epr ope r t i e soft hel ogar i t hm f unc t i onwi t ht hee x c e pt i onof A)l n( 1/x)=l n( x) . B)l n( a+x)=l n( a )+l n( x) . C)l n( a x)=l n( a )+l n( x) . D)l n( xa )al n( x) . Ans we r :B 20)Thebi nar yvar i abl ei nt e r a c t i onr e gr e s s i on A)c anonl ybeappl i e dwhe nt he r ear et wobi nar yvar i abl e s ,butnott hr e eormor e . B)i st hes ameast e s t i ngf ordi ffe r e nc e si nme ans . C)c annotbeus e dwi t hl ogar i t hmi cr e gr e s s i onf unc t i onsbe c aus el n( 0)i snotde fine d. D)al l owst hee ffe c tofc hangi ngoneoft hebi nar yi nde pe nde ntvar i abl e st ode pe ndont heval ueoft he ot he rbi nar yvar i abl e . Ans we r :D 21)I nt her e gr e s s i onmode lYi=β Xi×Di )+ui ,whe r eXi sac ont i nuousvar i abl eand 0+β 1Xi+β 2Di+β 3( Di sabi nar yvar i abl e ,β 3 A)i ndi c a t e st hes l opeoft her e gr e s s i onwhe nD=1. B)hasas t andar de r r ort ha ti snotnor mal l ydi s t r i but e de ve ni nl ar ges ampl e ss i nc eDi snotanor mal l y di s t r i but e dvar i abl e . C)i ndi c a t e st hedi ffe r e nc ei nt hes l ope soft het wor e gr e s s i ons . D)hasnome ani ngs i nc e( Xi×Di )=0whe nDi=0. Ans we r :C 22)I nt her e gr e s s i onmode lYi=β Xi×Di )+ui ,whe r eXi sac ont i nuousvar i abl eand 0+β 1Xi+β 2Di+β 3( Di sabi nar yvar i abl e ,β 2 A)i st hedi ffe r e nc ei nme ansi nYbe t we e nt het woc a t e gor i e s . B)i ndi c a t e st hedi ffe r e nc ei nt hei nt e r c e pt soft het wor e gr e s s i ons . C)i sus ual l ypos i t i ve . D)i ndi c a t e st hedi ffe r e nc ei nt hes l ope soft het wor e gr e s s i ons . Ans we r :B 23)I nt her e gr e s s i onmode lYi=β Xi×Di )+ui ,whe r eXi sac ont i nuousvar i abl eand 0+β 1Xi+β 2Di+β 3( Di sabi nar yvar i abl e ,t ot e s tt ha tt het wor e gr e s s i onsar ei de nt i c al ,youmus tus et he A)t s t a t i s t i cs e par a t e l yf orβ 2=0,β 2=0. B)Fs t a t i s t i cf ort hej oi nthypot he s i st ha tβ β 0=0, 1=0. C)t s t a t i s t i cs e par a t e l yf orβ 3=0. D)Fs t a t i s t i cf ort hej oi nthypot he s i st ha tβ 2=0,β 3=0. Ans we r :D 5 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 24)I nt hemode lYi=β X1×X2)+ui ,t hee xpe c t e de ffe c t 0+β 1X1+β 2X2+β 3( i s A)β 1+β 3X2. B)β . 1 C)β 1+β 3. D)β + β 1 3X1. Ans we r :A 25)I nt hel ogl ogmode l ,t hes l opec oe ffic i e nti ndi c a t e s A)t hee ffe c tt ha tauni tc hangei nXhasonY. B)t hee l as t i c i t yofYwi t hr e s pe c tt oX. C)ΔY/ΔX. D) × . Ans we r :B 26)I nt hemode ll n( Yi )=β ,t hee l as t i c i t yofE( Y|X)wi t hr e s pe c tt oXi s 0+β 1Xi+ui A)β 1X B)β 1 C) D)Cannotbec al c ul a t e dbe c aus et hef unc t i oni snonl i ne ar Ans we r :A 27)As s umet ha tyouhade s t i ma t e dt hef ol l owi ngquadr a t i cr e gr e s s i onmode l 2 =607. 3+3. 85I nc o me-0. 0423I nc o me.I fi nc omei nc r e as e df r om 10t o11( $10, 000t o$11 , 000) ,t he n t hepr e di c t e de ffe c tont e s t s c or e swoul dbe A)3. 85 B)3. 850. 0423 C)Cannotbec al c ul a t e dbe c aus et hef unc t i oni snonl i ne ar D)2. 96 Ans we r :D 28)Cons i de rt hepol ynomi alr e gr e s s i onmode lofde gr e eYi=β 0+β 1Xi+β 2 +. . . +β r +ui .Ac c or di ng t ot henul lhypot he s i st ha tt her e gr e s s i oni sl i ne arandt heal t e r na t i vet ha ti sapol ynomi alofde gr e er c or r e s pondst o A)H0:β .β r=0vs r≠ 0 B)H0:β .β r=0vs 1≠ 0 C)H0:β = 0 , . . . , β .H1:al lβ ≠ 0,j =3,. . . ,r 3 r=0,vs j D)H0:β . . ,β . H1:a tl e as toneβ ≠ 0,j =2,. . . ,r 2=0,β 3=0. r=0,vs j Ans we r :D 6 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 29)Cons i de rt hef ol l owi ngl e as ts quar e ss pe c i fic a t i onbe t we e nt e s t s c or e sandt hes t ude nt t e ac he rr a t i o: =557. 8+36. 42l n( I nc o me ) .Ac c or di ngt ot hi se qua t i on,a1% i nc r e as ei nc omei sas s oc i a t e dwi t h ani nc r e as ei nt e s ts c or e sof A)0. 36poi nt s B)36. 42poi nt s C)557. 8poi nt s D)c annotbede t e r mi ne df r om t hei nf or ma t i ongi ve nhe r e Ans we r :A 30)Cons i de rt hepopul a t i onr e gr e s s i onofl oge ar ni ngs[ Yi ,whe r eYi=l n( Ea r ni ng s ) ]a gai ns tt wobi nar y i t hpe var i abl e s :whe t he rawor ke ri smar r i e d( D1i ,whe r eD1i =1i ft hei r s oni smar r i e d)andt hewor ke r ' s t hpe ge nde r( D2i ,whe r eD2i =1i ft hei r s oni sf e mal e ) ,andt hepr oduc toft het wobi nar yvar i abl e s Yi=β0+β D + β D + β ( D × D ) + u . T h e i n t e r a c t i o n t e r m 1 1i 2 2i 3 1i 2i i A)al l owst hepopul a t i one ffe c tonl oge ar ni ngsofbe i ngmar r i e dt ode pe ndonge nde r B)doe snotmakes e ns es i nc ei tc oul dbez e r of ormar r i e dmal e s C)i ndi c a t e st hee ffe c tofbe i ngmar r i e donl oge ar ni ngs D)c annotbee s t i ma t e dwi t houtt hepr e s e nc eofac ont i nuousvar i abl e Ans we r :A 7 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 8. 2 Es s a ysandLonge rQue s t i ons 1)Fe mal e s ,i ti ss ai d,make70c e nt st ot hedol l ari nt heUni t e dSt a t e s .Toi nve s t i ga t et hi sphe nome non,you c ol l e c tda t aonwe e kl ye ar ni ngsf r om 1, 744i ndi vi dual s ,850f e mal e sand894mal e s .Ne xt ,youc al c ul a t e t he i ra ve r a gewe e kl ye ar ni ngsandfindt ha tt hef e ma l e si nyours ampl ee ar ne d$346. 98,whi l et hemal e s made$517. 70. ( a)Cal c ul a t et hef e mal ee ar ni ngsi npe r c e ntoft hemal ee ar ni ngs .How woul dyout e s twhe t he rornott hi s di ffe r e nc ei ss t a t i s t i c al l ys i gni fic ant ?Gi vet woappr oac he s . ( b)Ape e rs ugge s t st ha tt hi si sc ons i s t e ntwi t ht hei de at ha tt he r ei sdi s c r i mi na t i ona gai ns tf e mal e si nt he l abormar ke t .Wha ti syourr e s pons e ? ( c )Your e c al lf r om yourt e xt bookt ha taddi t i onalye ar sofe xpe r i e nc ear es uppos e dt or e s ul ti nhi ghe r e ar ni ngs .Your e as ont ha tt hi si sbe c aus ee xpe r i e nc ei sr e l a t e dt o" ont hej obt r ai ni ng. "Onef r e que nt l yus e d me as ur ef or( pot e nt i al )e xpe r i e nc ei s" Age Educ a t i on6. "Expl ai nt heunde r l yi ngr a t i onal e .As s umi ng, he r oi c al l y ,t ha te duc a t i oni sc ons t antac r os st he1, 744i ndi vi dual s ,youc ons i de rr e gr e s s i nge ar ni ngsona ge andabi nar yvar i abl ef orge nde r .Youe s t i ma t et wos pe c i fic a t i onsi ni t i al l y: =323. 70+5. 15×Ag e–169. 78×Fe ma l e ,R2=0. 13,SER=274. 75 ( 21. 18) ( 0. 55) ( 13. 06) =5. 44+0. 015×Ag e–0. 421×Fe ma l e ,R2=0. 17,SER=0. 75 ( 0. 08)( 0. 002) ( 0. 036) whe r eEa r nar ewe e kl ye ar ni ngsi ndol l ar s ,Ag ei sme as ur e di nye ar s ,andFe ma l ei sabi nar yvar i abl e , whi c ht ake sont heval ueofonei ft hei ndi vi duali saf e mal eandi sze r oot he r wi s e .I nt e r pr e te ac h r e gr e s s i onc ar e f ul l y .Foragi ve na ge ,how muc hl e s sdof e mal e se ar nona ve r a ge ?Shoul dyouc hoos et he s e c onds pe c i fic a t i onongr oundsoft hehi ghe rr e gr e s s i onR2? ( d)Yourpe e rpoi nt soutt oyout ha ta ge e ar ni ngpr ofil e st ypi c al l yt akeonani nve r t e dUs hape .Tot e s tt hi s i de a ,youaddt hes quar eofa get oyourl ogl i ne arr e gr e s s i on. 2, =3. 04+0. 147×Ag e–0. 421×Fe ma l e–0. 0016Ag e ( 0. 18)( 0. 009) ( 0. 033) ( 0. 0001) R2=0. 28,SER=0. 68 8 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 I nt e r pr e tt her e s ul t sa gai n.Ar et he r es t r ongr e as onst oas s umet ha tt hi ss pe c i fic a t i oni ss upe r i ort ot he pr e vi ousone ?Whyi st hei nc r e as eoft heAg ec oe ffic i e nts ol ar ger e l a t i vet oi t sval uei n( c ) ? ( e )Wha tot he rf a c t or sma ypl a yar ol ei ne ar ni ngsde t e r mi na t i on? Ans we r : ( a)Fe mal ee ar ni ngsar ea t67pe r c e ntofmal ee ar ni ngs .Thedi ffe r e nc ei nme anst e s tde s c r i be di ns e c t i on 3. 4oft het e xt .Thet s t a t i s t i cf orc ompar i s onoft wome ansi sgi ve ni ne qua t i on( 3. 20) ,whi c hi sonewa yt o t e s tf ors t a t i s t i c als i gni fic anc e .Theal t e r na t i vei st or unar e gr e s s i onofe ar ni ngsonac ons t antandabi nar y var i abl e ,whi c ht ake sont heval ueofonef orf e mal e sandi sze r oot he r wi s e .Us i ngat t e s tont hes l opeof t hebi nar yvar i abl eamount st ot hes amet e s tast hedi ffe r e nc ei nme ans( s e c t i on4. 7i nt het e xt ) . ( b)Di ffe r e nc e si na t t r i but e soft hei ndi vi dual s ,s uc hase duc a t i on,abi l i t y ,andt e nur ewi t hane mpl oye r , ha venotbe e nt ake ni nt oac c ount .He nc e ,i ni t s e l f ,t hi si swe ake vi de nc e ,a tbe s t ,f ordi s c r i mi na t i on. ( c )Thepot e nt i ale xpe r i e nc evar i abl ei sar e as onabl epr oxyf or" ont hej obt r ai ni ng"i ft hei ndi vi dual s t ar t e dt owor kaf t e rc ompl e t i nghe rorhi se duc a t i on,ands t a ye de mpl oye dt he r e af t e r .He nc et hi si sa be t t e rpr oxyf ors omet hanf orot he r s . Thel i ne ars pe c i fic a t i ons ugge s t st ha tf ore ve r yaddi t i onalye art hei ndi vi dualr e c e i ve s$5. 15ofaddi t i onal we e kl ye ar ni ngsona ve r a ge .Fe mal e smake$167. 78l e s st hanmal e sa tagi ve na ge .The r ei snoda t ac l os et o t heor i gi n,s ot hei nt e r c e pts houl dnotbei nt e r pr e t e d.Ther e gr e s s i one xpl ai ns13pe r c e ntoft hevar i a t i on i ne ar ni ngs . Thel ogl i ne ars pe c i fic a t i ons a yst ha te ar ni ngsi nc r e as eby1. 5pe r c e ntf ore ve r yaddi t i onalye a ri nan i ndi vi dual ' sl i f e .Fe mal e se ar nappr oxi ma t e l y42. 1pe r c e ntl e s st hanmal e sa tagi ve na ge .Agai n,t he i nt e r c e pts houl dnotbei nt e r pr e t e d.Ther e gr e s s i one xpl ai ns17pe r c e ntoft hevar i a t i oni nt hel ogof e ar ni ngs .Yous houl dnotpr e f e rt hi ss pe c i fic a t i onove rt hel i ne aroneongr oundsoft hehi ghe rr e gr e s s i on R2s i nc et he s ec annotbec ompar e dasar e s ul toft hedi ffe r e nc ei nt heuni t sofme as ur e me ntoft he de pe nde ntvar i abl e . ( d)Thec oe ffic i e ntont headde dvar i abl ei ss t a t i s t i c al l ys i gni fic antandhasr e s ul t e di nas ubs t ant i al 2 i nc r e as ei nt her e gr e s s i onR .Thei nc r e as ei nt heAg ec oe ffic i e nti sduet ot hef ac tt ha te ar ni ngsi nc r e as e mor ei ni t i al l yt hanl a t e ri nl i f eor ,ma t he ma t i c al l ys pe aki ng,i tc ompe ns a t e sf ort hene ga t i vec oe ffic i e nton 2,whi Ag e c hl owe r se ar ni ngsasi ndi vi dual sbe c omeol de r . ( e )St ude nt s ' ans we r swi l ldi ffe r ,bute duc a t i on,abi l i t y ,r e gi onaldi ffe r e nc e s ,r ac e ,andpr of e s s i onalc hoi c e ar eof t e nme nt i one d. 9 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 2)Ane xt e ns i onoft heSol ow gr owt hmode lt ha ti nc l ude shumanc api t ali naddi t i ont ophys i c alc api t al , s ugge s t st ha ti nve s t me nti nhumanc api t al( e duc a t i on)wi l li nc r e as et hewe al t hofana t i on( pe rc api t a i nc ome ) .Tot e s tt hi shypot he s i s ,youc ol l e c tda t af or104c ount r i e sandpe r f or mt hef ol l owi ngr e gr e s s i on: =0. 046–5. 869×gpo p+0. 738×SK+0. 055×Educ ,R2=0. 775,SER=0. 1377 ( 0. 079) ( 2. 238) ( 0. 294) ( 0. 010) whe r eRe l Pe r s I nci sGDPpe rwor ke rr e l a t i vet ot heUni t e dSt a t e s ,gpo pi st hea ve r a gepopul a t i ongr owt h r a t e ,1980t o1990,s Ki st hea ve r a gei nve s t me nts har eofGDPf r om 1960t o1990,andEduci st hea ve r a ge e duc a t i onala t t ai nme nti nye ar sf or1985.Numbe r si npar e nt he s e sar ef orhe t e r os ke das t i c i t yr obus t s t andar de r r or s . ( a)I nt e r pr e tt her e s ul t sandi ndi c a t ewhe t he rornott hec oe ffic i e nt sar es i gni fic ant l ydi ffe r e ntf r om z e r o. Dot hec oe ffic i e nt sha vet hee xpe c t e ds i gn? ( b)Tot e s tf ore qual i t yoft hec oe ffic i e nt sbe t we e nt heOECDandot he rc ount r i e s ,youi nt r oduc eabi nar y var i abl e( DOECD) ,whi c ht ake sont heval ueofonef ort heOECDc ount r i e sandi sze r oot he r wi s e .To c onduc tt het e s tf ore qual i t yoft hec oe ffic i e nt s ,youe s t i ma t et hef ol l owi ngr e gr e s s i on: =0. 068–0. 063×gpo p+0. 719×SK+0. 044×Educ , ( 0. 072) ( 2. 271) ( 0. 365) ( 0. 012) 0. 381×DOECD –8. 038×( DOECD ×gpo p) -0. 430×( DOECD ×SK) ( 0. 184) ( 5. 366) ( 0. 768) +0. 003×( DOECD ×Educ ) ,R2=0. 845,SER=0. 116 ( 0. 018) Wr i t edownt het wor e gr e s s i onf unc t i ons ,onef ort heOECDc ount r i e s ,t heot he rf ort henonOECD c ount r i e s .TheF-s t a t i s t i ct ha tal lc oe ffic i e nt si nvol vi ngDOECD ar ez e r o,i s6. 76.Fi ndt hec or r e s pondi ng c r i t i c alval uef r om t heFt abl eandde c i dewhe t he rornott hec oe ffic i e nt sar ee qualac r os st het wos e t sof c ount r i e s . ( c )Gi ve nyourans we ri nt hepr e vi ousque s t i on,youwantt oi nve s t i ga t ef ur t he r .Youfir s tf or c et hes a me s l ope sac r os sal lc ount r i e s ,butal l ow t hei nt e r c e ptt odi ffe r .Tha ti s ,your e e s t i ma t et heabover e gr e s s i on buts e tβ s t a t i s t i cf orDOECD i s4. 39.I st he DOECD ×gpo p=β DOECD × =β DOECD ×Educ=0.Thet c oe ffic i e nt ,whi c hwas0. 241,s t a t i s t i c al l ys i gni fic ant ? ( d)Yourfinalr e gr e s s i onal l owst hes l ope st odi ffe ri naddi t i ont ot hei nt e r c e pt .TheFs t a t i s t i cf or β s1. 05.Wha ti syourde c i s i on?Eac honeoft het DOECD ×Educ=0i DOECD ×gpo p=β DOECD × =β s t a t i s t i c si sal s os mal l e rt hant hec r i t i c alval uef r om t hes t andar dnor malt abl e .Whi c ht e s ts houl dyouus e ? ( e )Looki nga tt het e s t si nt het wopr e vi ousque s t i ons ,wha ti syourc onc l us i on? 10 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 Ans we r : ( a)Aonepe r c e nt a gepoi ntde c r e as ei nt hepopul a t i ongr owt hr a t ei nc r e as e sGDPpe rwor ke rr e l a t i vet o t heUni t e dSt a t e sbyr oughl y0. 06.Ani nc r e as ei nt hei nve s t me nts har eof0. 1r e s ul t si nani nc r e as eofGDP pe rwor ke rr e l a t i vet ot heUni t e dSt a t e sbyappr oxi ma t e l y0. 07.Fore ve r yaddi t i onalye a rofa ve r a ge e duc a t i onala t t ai nme nt ,t hei nc r e as ei s0. 055.Thei nt e r c e pts houl dnotbei nt e r pr e t e d.Ther e gr e s s i on e xpl ai ns77. 5pe r c e ntoft hevar i a t i oni nr e l a t i vepr oduc t i vi t y .Al lc oe ffic i e nt sar es i gni fic ant l ydi ffe r e nt f r om ze r oa tc onve nt i onall e ve l s .Al lc oe ffic i e nt sc a r r yt hee xpe c t e ds i gn. ( b)Ther e gr e s s i onf ort henonOECDc ount r i e si s =0. 068–0. 063×gpo p+0. 719×SK+0. 044×Educ . Fort heOECDc ount r i e swege t =0. 313–8. 101×gpo p+0. 289×SK+0. 047×Educ . Thec r i t i c alval uei s3. 32a tt he1% l e ve landhe nc eyouc anr e j e c tt henul lhypot he s i st ha tt hec oe ffic i e nt s ar ee qual . ( c )Ans we r :Gi ve nt hec r i t i c alval ue ,t hec oe ffic i e nti ss t a t i s t i c al l ys i gni fic ant ,t ha ti s ,youc anr e j e c t β DOECD =0. ( d)Gi ve nt hec r i t i c alval ueof3. 78a tt he1% l e ve l ,youc annotr e j e c tt henul lhypot he s i st ha tt headdi t i onal c oe ffic i e nt sar eal lz e r o.TheFt e s ti st hepr ope rpr oc e dur et ous ewhe nt e s t i ngf ors i mul t ane ous r e s t r i c t i ons . ( e )The r ei se vi de nc et ha tt hes l ope sc anbes e te qual .Howe ve r ,t he r es e e mst obeal e ve ldi ffe r e nc e be t we e nt het wogr oupsofc ount r i e s . 11 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 3)Youha vebe e nas ke dbyyouryounge rs i s t e rt ohe l phe rwi t has c i e nc ef ai rpr oj e c t .Dur i ngt hepr e vi ous ye ar ss heal r e adys t udi e dwhyobj e c t sfloa tandt he r eal s owast hei ne vi t abl evol c anopr oj e c t .Ha vi ng l e ar ne dr e gr e s s i ont e c hni que sr e c e nt l y ,yous ugge s tt ha ts hei nve s t i ga t et hewe i ght he i ghtr e l a t i ons hi pof ht hgr 4t o6t ade r s .He rpr e s e nt a t i ont opi cwi l lbet oe xpl ai nhow pe opl ea tc ar ni val spr e di c twe i ght .You c ol l e c tda t af orr oughl y100boysandgi r l sbe t we e nt hea ge sofni neandt we l veande s t i ma t ef orhe rt he f ol l owi ngr e l a t i ons hi p: 4,R2=0. =45. 59+4. 32×He i g ht 55,SER=15. 69 ( 3. 81) ( 0. 46) whe r eWe i g hti si npounds ,andHe i g ht 4i si nc he sabove4f e e t . ( a)I nt e r pr e tt her e s ul t s . ( b)Your e me mbe rf r om t heme di c all i t e r a t ur et ha tf e mal e si nt headul tpopul a t i onar e ,ona ve r a ge ,s hor t e r t hanmal e sandwe i ghl e s s .Youal s os e e mt oha vehe ar dt ha tf e mal e s ,c ont r ol l i ngf orhe i ght ,ar es uppos e d t owe i ghl e s st hanmal e s .Tos e ei ft hi sr e l a t i ons hi phol dsf orc hi l dr e n,youaddabi nar yvar i abl e( DFY) t ha tt a ke sont heval ueonef orgi r l sandi sze r oot he r wi s e .Youe s t i ma t et hef ol l owi ngr e gr e s s i onf unc t i on: =36. 27+17. 33×DFY+5. 32×He i g ht 4–1. 83×( DFY×He i g ht 4) , ( 5. 99) ( 7. 36) ( 0. 80) ( 0. 90) R2=0. 58,SER=15. 41 Ar et hes i gnsont hene wc oe ffic i e nt sase xpe c t e d?Ar et hene wc oe ffic i e nt si ndi vi dual l ys t a t i s t i c al l y s i gni fic ant ?Wr i t edownands ke t c ht her e gr e s s i onf unc t i onf orboysandgi r l ss e par a t e l y . ( c )Theme di c all i t e r a t ur epr ovi de syouwi t ht hef ol l owi ngi nf or ma t i onf orme di anhe i ghtandwe i ghtof ni ne -t ot we l ve ye ar ol ds : Medi anHei ghtandWei ghtf orChi l dr en,Age912 9ye ar ol d 10ye ar ol d 11ye ar ol d 12ye ar ol d Boys ' We i ght Boys ' He i ght Gi r l s ' We i ght Gi r l s ' He i ght 60 52 60 49 70 54 70 52 77 56 80 57 87 58. 5 92 60 I ns e r tt wohe i ght /we i ghtme as ur e se ac hf orboysandgi r l sands e ehow ac c ur a t eyourpr e di c t i onsar e . ( d)TheFs t a t i s t i cf ort e s t i ngt ha tt hei nt e r c e ptands l opef orboysandgi r l sar ei de nt i c ali s2. 92.Fi ndt he c r i t i c alval ue sa tt he5% and1% l e ve l ,andmakeade c i s i on.Al l owi ngf oradi ffe r e nti nt e r c e ptwi t han i de nt i c als l oper e s ul t si nat s t a t i s t i cf orDFYof( –0. 35) .Ha vi ngi de nt i c ali nt e r c e pt sbutdi ffe r e nts l ope s gi ve sat s t a t i s t i con( DFYHe i ght 4)of( –0. 35)al s o.Doe st hi saffe c tyourpr e vi ousc onc l us i on? ( e )As s umet ha tyoual s owant e dt ot e s ti ft her e l a t i ons hi pc hange sbya ge .Br i e flyout l i nehow youwoul d s pe c i f yt her e gr e s s i oni nc l udi ngt hege nde rbi nar yvar i abl eandana gebi nar yvar i abl e( Ol de r )t ha tt ake s onaval ueofonef ore l e ve nt ot we l veye arol dsandi sz e r oot he r wi s e .I ndi c a t ei nat abl eoft wor owsand t woc ol umnshow t hee s t i ma t e dr e l a t i ons hi pwoul dvar ybe t we e nyounge rgi r l s ,ol de rgi r l s ,younge rboys , andol de rboys . Ans we r : ( a)Fore ve r yi nc habove4f e e t ,c hi l dr e noft ha ta gegr oupgai nr oughl y4pounds .As t ude ntwhoi s4f e e t t al l ,we i ghsappr oxi ma t e l y45. 5pounds .Ther e gr e s s i one xpl ai ns55pe r c e ntoft hewe i ghtvar i a t i oni n c hi l dr e noft ha ta gegr oup. ( b)Shor t e rgi r l swe i ghtmor et hanboys ,andt al l e rboyswe i ghmor et hangi r l sona ve r a ge .Gi ve nyour pr i ore xpe c t a t i ons ,t hi si ss ome wha tune xpe c t e d.Thec oe ffic i e nt si nvol vi ngt hebi nar yvar i abl ear e 12 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 s t a t i s t i c al l ys i gni fic anta tc onve nt i onall e ve l s .Ther e gr e s s i onsf orboysi s =36. 27+5. 32×He i g ht 4. Forgi r l si ti s =53. 60+3. 49×He i g ht 4. ( c )The" XX"poi nt smar kaf e mal e ,andt he" XY"amal e .Ther e gr e s s i onl i nepr e di c t sa9ye a r ol dboyt o we i gh57. 2pounds ,an11ye a r ol dboyt owe i gh78. 8pounds ,a10ye ar -ol dgi r lt owe i gh67. 6anda12ye a r ol dgi r lt owe i gh95. 5pounds .He nc et hewe i ght sar equi t ec l os e . 13 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( d)Thec r i t i c alval uei s3. 00a tt he5% l e ve l ,and4. 61a tt he1% l e ve l .He nc eyouc annotr e j e c te qua l i t yof t het woc oe ffic i e nt s .Thepr e vi ousc onc l us i oni sunaffe c t e ds i nc et het e s twasf orbot hhypot he s e st ohol d s i mul t ane ous l y .Thet s t a t i s t i c si ndi c a t et ha ti mpos i ngt hee qual i t yandt e s t i ngf ore i t he rt hes l opeort he i nt e r c e ptt obes i gni fic ant l ydi ffe r e ntbe t we e nboysandgi r l s ,doe snotr e s ul ti nadi ffe r e ntc oe ffic i e nt e i t he r . ( e )We i g ht=β i g ht 4+β DFY×He i g ht 4) 0+β 1DFY+β 2He 3( +β de r+β Ol de r×He i g ht 4)+u 4Ol 5( Boys Younge r + H e i ht 4 0 2 g Ol de r (0+ 4)+(2+ 5)He i g ht 4 Gi r l s (0+ 1)+(2+ 3)He i g ht 4(0+ 1+ 4)+(2+ 3+ 5)He i g ht 4 14 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 4)Youha vel e ar ne dt ha te ar ni ngsf unc t i onsar eoneoft hemos ti nve s t i ga t e dr e l a t i ons hi psi ne c onomi c s . The s et ypi c al l yr e l a t et hel ogar i t hm ofe ar ni ngst oas e r i e sofe xpl ana t or yvar i abl e ss uc hase duc a t i on, wor ke xpe r i e nc e ,ge nde r ,r ac e ,e t c . ( a)Whydoyout hi nkt ha tr e s e ar c he r sha vepr e f e r r e dal ogl i ne ars pe c i fic a t i onove ral i ne ars pe c i fic a t i on? I naddi t i ont ot hei nt e r pr e t a t i onoft hes l opec oe ffic i e nt s ,al s ot hi nkaboutt hedi s t r i but i onoft hee r r or t e r m. ( b)Toe s t abl i s ha ge e ar ni ngspr ofil e s ,your e gr e s sl n( Ea r n)onAge ,whe r eEa r ni swe e kl ye ar ni ngsi n dol l ar s ,andAg ei si nye ar s .Pl ot t i ngt her e s i dual soft her e gr e s s i ona gai ns ta gef or1, 744i ndi vi dual sl ooks ass howni nt hefigur e : Doyous e ns eapr obl e m? ( c )Youde c i de ,gi ve nyourknowl e dgeofa ge e ar ni ngpr ofil e s ,t oal l ow t her e gr e s s i onl i net odi ffe rf ort he be l ow andabove40ye ar sa gec a t e gor y .Ac c or di ngl yyouc r e a t eabi nar yvar i abl e ,Da g e ,t ha tt ake st heval ue onef ora ge39andbe l ow,andi sz e r oot he r wi s e .Es t i ma t i ngt hee ar ni ngse qua t i onr e s ul t si nt hef ol l owi ng out put( us i nghe t e r os ke das t i c i t yr obus ts t andar de r r or s ) : =6. 92–3. 13×Da g e–0. 019×Ag e+0. 085×( Da g e×Ag e ) ,R2=0. 20,SER=0. 721. ( 38. 33)( 0. 22) ( 0. 004) ( 0. 005) Ske t c hbot hr e gr e s s i onl i ne s :onef ort hea gec a t e gor y39ye ar sandunde r ,andonef or40andabove .Doe s i tmakes e ns et oha veane ga t i ves i gnont heAgec oe ffic i e nt ?Pr e di c tt hel n( e a r ni ng s )f ora30ye a rol danda 50ye a rol d.Wha ti st hepe r c e nt a gedi ffe r e nc ebe t we e nt he s et wo? ( d)TheFs t a t i s t i cf ort hehypot he s i st ha tbot hs l ope sandi nt e r c e pt sar et hes amei s124. 43.Canyour e j e c t t henul lhypot he s i s ? ( e )Wha tot he rf unc t i onalf or mss houl dyouc ons i de r ? 15 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 Ans we r : ( a)Thee r r orvar i anc eandt hevar i anc eoft hede pe nde ntvar i abl ear er e l a t e d.Gi ve nt ha tt hede pe nde nt var i abl e( e ar ni ngs )i snotnor mal l ydi s t r i but e d,i ti sdi ffic ul tt opos t ul a t et ha tt hee r r orvar i anc ei s nor mal l ydi s t r i but e d.Us i ngl ogar i t hmsr e s ul t si nadi s t r i but i ont ha ti sc l os e rt oanor mal .I naddi t i on, t he r es e e mst obeabe t t e rfitf ort hel ogl i ne ars pe c i fic a t i on,andt hec oe ffic i e nt sc anbei nt e r pr e t e das pe r c e nt a gec hange s . ( b)The r es e e mst obeapa t t e r ni nt her e s i dual swhe ns or t e dbya ge .Thi ss ugge s t sami s s pe c i fie d f unc t i onalf or m. ( c )Ac c or di ngt ot hes pe c i fic a t i on,e ar ni ngsi nc r e as ewi t ha geunt i lt hei ndi vi duali s39ye ar sol d.I ti sonl y f r om a ge40onwar dst ha tt her e gr e s s i onpr e di c t sane ga t i ver e l a t i ons hi pbe t we e ne ar ni ngsanda ge . Ac c or di ngt ot hee s t i ma t e s ,a30ye a r ol dwoul dha vel n( e a r ni ng s )of5. 77,whi l et hepr e di c t e dval uef ora 50ye ar ol dwoul dbe5. 97.Thedi ffe r e nc ebe t we e nt het woi sappr oxi ma t e l y20pe r c e nt . ( d)Thec r i t i c alval uef r om t heFt abl ei s4. 61a tt he1% l e ve l .He nc et henul lhypot he s i si sr e j e c t e d. ( e )I ns t e adoft hei nve r t e dVs hapef ort heabover e gr e s s i on,ani nve r t e dUs hapewoul dmos tl i ke l y pr oduc eabe t t e rfit .Thi sc anbege ne r a t e dt hr ought heus eofapol ynomi alr e gr e s s i onmode lofde gr e e2. 16 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 5)Spor t se c onomi c st ypi c al l yl ooksa twi nni ngpe r c e nt a ge sofs por t st e amsasoneofvar i ousout put s ,and e s t i ma t e spr oduc t i onf unc t i onsbyana l yzi ngt her e l a t i ons hi pbe t we e nt hewi nni ngpe r c e nt a geandi nput s . I nMa j orLe a gueBas e bal l( MLB) ,t hede t e r mi nant sofwi nni ngar equal i t ypi t c hi ngandba t t i ng.Al l30 MLBt e amsf ort he1999s e as on.Pi t c hi ngqual i t yi sappr oxi ma t e dby" Te am Ear ne dRunAve r a ge "( ERA) , andhi t t i ngqual i t yby" OnBas ePl usSl uggi ngPe r c e nt a ge "( OPS) . Summar yoft heDi s t r i but i onofWi nni ngPer c ent age ,OnBas ePl usSl uggi ngPer c ent age , andTe am Ea r nedRunAver agef orMLBi n1999 Aver age St andar d Per c ent i l e devi a t i on 10% 25% 40% 50% 60% 75% 90% ( medi an) Te am ERA 4. 71 0. 53 3. 84 4. 35 4. 72 4. 78 4. 91 5. 06 5. 25 OPS 0. 778 0. 034 0. 720 0. 754 0. 769 0. 780 0. 790 0. 798 0. 820 Wi nni ng 0. 50 0. 08 0. 40 0. 43 0. 46 0. 48 0. 49 0. 59 0. 60 Pe r c e nt a ge Yourr e gr e s s i onout puti s : =–0. 19–0. 099×t e a me r a+1. 490×o ps ,R2=0. 92,SER=0. 02. ( 0. 08)( 0. 008) ( 0. 126) ( a)I nt e r pr e tt her e gr e s s i on.Ar et her e s ul t ss t a t i s t i c al l ys i gni fic antandi mpor t ant ? ( b)The r ear et wol e a gue si nMLB,t heAme r i c anLe a gue( AL)andt heNa t i onalLe a gue( NL) .Onema j or di ffe r e nc ei st ha tt hepi t c he ri nt heALdoe snotha vet oba t .I ns t e adt he r ei sa" de s i gna t e dhi t t e r "i nt he hi t t i ngl i ne up.Youar ec onc e r ne dt ha t ,asar e s ul t ,t he r ei sadi ffe r e nte ffe c tofpi t c hi ngandhi t t i ngi nt he ALf r om t heNL.Tot e s tt hi shypot he s i s , youal l ow t heALr e gr e s s i ont oha veadi ffe r e nti nt e r c e ptand di ffe r e nts l ope sf r om t heNLr e gr e s s i on.Yout he r e f or ec r e a t eabi nar yvar i abl ef ort heAme r i c anLe a gue ( DAL)ande s t i ma t et hef ol l owi ngs pe c i fic a t i on: =–0. 29+0. 10×DAL–0. 100×t e a me r a+0. 008×( DAL×t e a me r a ) ( 0. 12)( 0. 24) ( 0. 008) ( 0. 018) +1. 622* o ps–0. 187* ( DAL×o ps ),R2=0. 92, SER=0. 02. ( 0. 163) ( 0. 160) Wha ti st her e gr e s s i onf orwi nni ngpe r c e nt a gei nt heALandNL?Ne xt ,c al c ul a t et het s t a t i s t i c sands a y s ome t hi ngaboutt hes t a t i s t i c als i gni fic anc eoft heALvar i abl e s .Si nc eyouha veal l owe dal ls l ope sandt he i nt e r c e ptt ovar ybe t we e nt het wol e a gue s ,wha twoul dt her e s ul t si mpl yi fal lc oe ffic i e nt si nvol vi ng DAL we r es t a t i s t i c al l ys i gni fic ant ? 17 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( c )Your e me mbe rt ha ts e que nt i al l yt e s t i ngt hes i gni fic anc eofs l opec oe ffic i e nt si snott hes ameast e s t i ng f ort he i rs i gni fic anc es i mul t ane ous l y .He nc eyouas kyourr e gr e s s i onpac ka get oc al c ul a t et heFs t a t i s t i c t ha tal lt hr e ec oe ffic i e nt si nvol vi ngt hebi nar yvar i abl ef ort heALar ez e r o.Yourr e gr e s s i onpac ka gegi ve sa val ueof0. 35.Looki nga tt hec r i t i c alval uef r om youFt abl e ,c anyour e j e c tt henul lhypot he s i sa tt he1% l e ve l ?Shoul dyouwor r yaboutt hes mal ls ampl es i ze ? Ans we r : ( a)Lowe r i ngt het e am ERAbyoner e s ul t si nawi nni ngpe r c e nt a gei nc r e as eofr oughl yt e npe r c e nt . I nc r e as i ngt heOPSby0. 1ge ne r a t e sahi ghe rwi nni ngpe r c e nt a geofappr oxi ma t e l y15pe r c e nt .The r e gr e s s i one xpl ai ns92pe r c e ntoft hevar i a t i oni nwi nni ngpe r c e nt a ge s .Bot hs l opec oe ffic i e nt sar e s t a t i s t i c al l ys i gni fic ant ,andgi ve nt hes mal ldi ffe r e nc e si nwi nni ngpe r c e nt a ge ,t he yar eal s oi mpor t ant . ( b)NL: =–0. 29–0. 100×t e a me r a+1. 622×o ps . AL: =–0. 19–0. 092×t e a me r a+1. 435×o ps . Thet s t a t i s t i c sf oral lvar i abl e si nvol vi ngDALar e ,i nor de rofappe ar anc ei nt heabover e gr e s s i on,0. 42, 0. 44,and–1. 17.Noneoft hec oe ffic i e nt si ss t a t i s t i c al l ys i gni fic anti ndi vi dual l y .I ft he s ewe r es t a t i s t i c al l y s i gni fic ant , t he nt hi swoul di ndi c a t et ha tt hec oe ffic i e nt svar ybe t we e nt het wol e a gue s .He nc ei twoul d s ugge s tt ha tt hei nt r oduc t i onoft hede s i gna t e dhi t t e rmi ghtha vec hange dt her e l a t i ons hi p. ( c )Thec r i t i c alval ueoft heFs t a t i s t i ci s3. 78a tt he1% l e ve l ,andhe nc eyouc annotr e j e c tt henul l hypot he s i s ,t ha tal lt hr e ec oe ffic i e nt sar ez e r o.Howe ve r ,t heFs t a t i s t i ci snotr e al l ydi s t r i but e dasF3, ∞, and,asar e s ul t ,i nf e r e nc ei spr obl e ma t i che r e . 18 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 6)The r ehasbe e nmuc hde ba t eaboutt hei mpac tofmi ni mum wa ge sone mpl oyme ntandune mpl oyme nt . Whi l emos toft hef oc ushasbe e nont hee mpl oyme nt t opopul a t i onr a t i ooft e e na ge r s ,youde c i det oc he c k i fa ggr e ga t es t a t eune mpl oyme ntr a t e sha vebe e na ffe c t e d.Youri de ai st os e ei fs t a t eune mpl oyme ntr a t e s f ort he48c ont i guousU. S.s t a t e si n1985c anpr e di c tt heune mpl oyme ntr a t ef ort hes ames t a t e si n1995, andi ft hi spr e di c t i onc anbei mpr ove duponbye nt e r i ngabi nar yvar i abl ef or" hi ghi mpac t "mi ni mum wa ges t a t e s .Onel abore c onomi s tl abe l e ds t a t e sashi ghi mpac ti fal ar gef r a c t i onoft e e na ge r swasa ffe c t e d byt he1990and1991f e de r almi ni mum wa gei nc r e as e s .Yourfir s tr e gr e s s i onr e s ul t si nt hef ol l owi ng out put : =3. 19+0. 27× ,R2=0. 21,SER=1. 031 ( 0. 56) ( 0. 07) ( a)Ske t c ht her e gr e s s i onl i neandadda450l i net ot hegr aph.I nt e r pr e tt her e gr e s s i onr e s ul t s .Wha twoul d t hei nt e r pr e t a t i onbei ft hefit t e dl i nec oi nc i de dwi t ht he450l i ne ? ( b)Addi ngt hebi nar yvar i abl eDhi I mpa c tbyal l owi ngt hes l opeandi nt e r c e ptt odi ffe r ,r e s ul t si nt he f ol l owi ngfit t e dl i ne : =4. 02+0. 16× ( 0. 66) ( 0. 09) –3. 25×Dhi I mpa c t+0. 38×( Dh i I mpa c t × ( 0. 89) ) , ( 0. 11) R2=0. 31,SER=0. 987 TheFs t a t i s t i cf ort henul lhypot he s i st ha tbot hpar ame t e r si nvol vi ngt hehi ghi mpac tmi ni mum wa ge var i abl ear eze r o,i s42. 16.Canyour e j e c tt henul lhypot he s i st ha tbot hc oe ffic i e nt sar ez e r o?Ske t c ht het wo r e gr e s s i onl i ne st oge t he rwi t ht he450l i neandi nt e r pr e tt her e s ul t sa gai n. ( c )Toc he c kt her obus t ne s soft he s er e s ul t s ,your e pe a tt hee x e r c i s eus i ngane w bi nar yvar i abl ef ort hes oc al l e dmi ni ngs t a t e( Dmi ni ng) ,i . e . ,t hee l e ve ns t a t e st ha tha vea tl e as tt hr e epe r c e ntoft he i rt ot als t a t e e ar ni ngsde r i ve df r om oi l ,gase xt r ac t i on,andc oalmi ni ng,i nt he1980s .Thi sr e s ul t si nt hef ol l owi ng out put : =4. 04+0. 15× ( 0. 65) ( 0. 09) –2. 92×Dmi ni ng+0. 37×( Dmi ni ng× ( 0. 90) ) , ( 0. 10) R2=0. 31,SER=0. 997 How c onfide ntar eyout ha tt hepr e vi ous l yf ounde ffe c ti sduet omi ni mum wa ge s ? 19 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 Ans we r : ( a)Ani nc r e as ei nt he1985une mpl oyme ntr a t er e s ul t si nani nc r e as ei nt heune mpl oyme ntr a t ei n1995of 0. 27pe r c e nt .Putdi ffe r e nt l y ,i fones t a t ehadaonepe r c e nthi ghe rune mpl oyme ntr a t ei n1985t hananot he r s t a t e ,t he nt hi sdi ffe r e nc ewoul ds hr i nk,ona ve r a ge ,t o0. 27pe r c e nti n1995.21pe r c e ntoft hevar i a t i oni n 1995s t a t eune mpl oyme ntr a t e si se xpl ai ne dbyt her e gr e s s i on.I ft hefit t e dl i nec oi nc i de dwi t ht he450l i ne , t he nt heune mpl oyme ntr a t e si n1995woul dr e mai nunc hange dwhe nc ompar e dt o1985.Thee s t i ma t e d r e gr e s s i oni mpl i e s ,unr e al i s t i c al l y ,me anr e ve r s i oni nt heune mpl oyme ntr a t e s . ( b)Thec r i t i c alval uef ort heFs t a t i s t i ci s4. 61a tt he1% l e ve landhe nc et henul lhypot he s i st ha tbot h c oe ffic i e nt sar ez e r oi nt hepopul a t i oni sr e j e c t e d.( Thes ampl es i zei ss mal l ,howe ve r ,s ot hedi s t r i but i onof t het e s ts t a t i s t i ci snotr e al l yknown. )Thei nt e r c e ptf ort hehi ghi mpac ts t a t e si ss mal l e randt hes l opei s s t e e pe r .Thi ss ugge s t st ha tf orhi ghi mpac ts t a t e st he r ei sl e s sofame anr e ve r s i one ffe c tpr e s e nt :i fhi ghi mpac ts t a t e shadhi gh1985une mpl oyme ntr a t e s ,t he nt he yar ee xpe c t e dt oha vehi ghe rune mpl oyme nt r a t e si n1995whe nc ompar e dt oal owi mpac ts t a t e .Hi ghandl ow une mpl oyme ntr a t e sar et he r e bymor e pe r s i s t e ntf orhi ghi mpac ts t a t e s . 20 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( c )Ther e s ul t she r ear es i mi l art ot hos ei n( b)i nt ha tt her e gr e s s i onf ort hemi ni ngs t a t e si ss t e e pe rt hant he onef ort heot he rs t a t e s .Pe r hapsomi t t e dvar i abl e spl a yar ol ehe r e ,s uc hasr e l a t i ve( oi l )pr i c es hoc kst ha t affe c ts omes t a t e smor et hanot he r s .Oi lpr i c e sf e l lc ons i de r abl yove rt het i mepe r i odandi ti spos s i bl et ha t t hehi ghi mpac tbi nar yvar i abl ec oe ffic i e ntpi c ksupt hee ffe c tofomi t t e dvar i abl e s .I nc l udi ngmor e e xpl ana t or yvar i abl e swoul dbede s i r abl e . 21 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 7)Labore c onomi s t sha vee xt e ns i ve l yr e s e ar c he dt hede t e r mi nant sofe ar ni ngs .I nve s t me nti nhuman c api t al ,me as ur e di nye ar sofe duc a t i on,andont hej obt r ai ni ngar es omeoft hemos ti mpor t ant e xpl ana t or yvar i abl e si nt hi sr e s e ar c h.Youde c i det oappl ye ar ni ngsf unc t i onst ot hefie l dofs por t s e c onomi c sbyfindi ngt hede t e r mi nant sf orbas e bal lpi t c he rs al ar i e s .Youc ol l e c tda t aon455pi t c he r sf or t he1998bas e bal ls e as onande s t i ma t et hef ol l owi nge qua t i onus i ngOLSandhe t e r os ke das t i c i t yr obus t s t andar de r r or s : =12. 45+0. 052×Ye a r s+0. 00089×I nni ng s+0. 0032×Sa v e s ( 0. 08) ( 0. 026) ( 0. 00020) ( 0. 0018) –0. 0085×ERA,R2=0. 45,SER=0. 874 ( 0. 0168) whe r eEa r ni sannuals al ar yi ndol l ar s ,Ye a r si snumbe rofye ar si nt hema j orl e a gue s ,I nni ng si snumbe rof i nni ngspi t c he ddur i ngt hec ar e e rbe f or et he1998s e as on,Sa v e si snumbe rofs a ve sdur i ngt hec ar e e r be f or et he1998s e as on,andERAi st hee ar ne dr una ve r a gebe f or et he1998s e as on. ( a)Wha thappe nst oe ar ni ngswhe nt hepi t c he rs t a ysi nt hel e a guef oroneaddi t i onalye ar ?Compar et he s al ar i e soft wor e l i e ve r s ,onewi t h10mor es a ve st hant heot he r .Wha te ffe c tdoe spi t c hi ng100mor e i nni ngsha veont hes al ar yoft hepi t c he r ?Wha te ffe c tdoe sr e duc i nghi sERA by1. 5?Dot hes i gns c or r e s pondt oyoure xpe c t a t i ons ?Expl ai n. ( b)Ar et hei ndi vi dualc oe ffic i e nt ss t a t i s t i c al l ys i gni fic ant ?I ndi c a t et hel e ve lofs i gni fic anc eyouus e dand t het ypeofal t e r na t i vehypot he s i syouc ons i de r e d. ( c )Al t houghyouar equi t ei mpr e s s e dwi t ht hefitoft her e gr e s s i on,s ome ones ugge s t st ha tyous houl d i nc l udet hes quar eofye ar sandi nni ngsasaddi t i onale xpl ana t or yvar i abl e s .Yourr e s ul t sc hangeas f ol l ows : =12. 15+0. 160×Ye a r s+0. 00268×I nni ng s+0. 0063×Sa v e s ( 0. 05) ( 0. 039) ( 0. 00030) ( 0. 0010) 2-0. 2 -0. 0584×ERA–0. 0165×Ye ar s 00000045×I nni ng s ( 0. 0165) ( 0. 0026) ( 0. 00000012) R2=0. 69,SER=0. 666 Wha ti she rr e as oni ng?Ar et hec oe ffic i e nt soft hequadr a t i ct e r mss t a t i s t i c al l ys i gni fic ant ?Ar et he y me ani ngf ul ? ( d)Cal c ul a t et hee ffe c tofmovi ngf r om t wot ot hr e eye ar s ,asoppos e dt of r om 12t o13ye ar s . ( e )Youal s ode c i det ot e s tt hes pe c i fic a t i onf ors t abi l i t yac r os sl e a gue s( Na t i onalLe a gueandAme r i c a n Le a gue )byi nc l udi ngadummyvar i abl ef ort heNa t i onalLe a gueandal l owi ngt hei nt e r c e ptandal ls l ope s t odi ffe r .Ther e s ul t i ngFs t a t i s t i cf orr e s t r i c t i ngal lc oe ffic i e nt st ha ti nvol vet heNa t i onalLe a guedummy var i abl et oze r o,i s0. 40.Compar et hi st ot her e l e vantc r i t i c alval uef r om t het abl eandde c i dewhe t he ror nott he s eaddi t i onalvar i abl e ss houl dbei nc l ude d. 22 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 Ans we r : ( a)Fors t a yi nganaddi t i onalye ari nt hel e a gue ,t hepi t c he rr e c e i ve sa5. 2pe r c e nti nc r e as ei ne ar ni ngs .On a ve r a ge ,t her e l i e ve rwi t h10mor es a ve se ndsupwi t h3. 2pe r c e nthi ghe re ar ni ngs .Pi t c hi ng100addi t i onal i nni ngsr e s ul t si n8. 9pe r c e nthi ghe re ar ni ngs ,andl owe r i ngt heERAby1. 5i nc r e as e se ar ni ngsby1. 3 pe r c e nt .ERA,i nni ngspi t c he d,andnumbe rofs a ve sar eal lqual i t yofi nputi ndi c a t or sands houl d t he r e f or eha vet hes i gnsasi nt her e gr e s s i onabove .Ye ar si nt hema j orl e a gue ss t andsasapr oxyf oront he j obt r ai ni ngands houl dt he r e f or ec ar r yapos i t i ves i gn. ( b)Gi ve nt ha tt he r ei spr i ore xpe c t a t i onont hes i gnoft hec oe ffic i e nt s ,yous houl dc onduc taones i de d hypot he s i st e s t .Al lvar i abl e swi t ht hee x c e pt i onofERAc ar r ys t a t i s t i c al l ys i gni fic antc oe ffic i e nt sa tt he5% l e ve l . ( c )Al l owi ngf ort hequadr a t i ct e r mst oe nt e rr e s ul t si nani nve r t e dUs hapef ort her e l a t i ons hi pbe t we e n t hel ogofe ar ni ngs ,andbot hye ar si nt hel e a gueandi nni ngspi t c he d.Bot hc oe ffic i e nt sar ehi ghl y s i gni fic antandha ver e s ul t e dal s oi nas i gni fic antERAc oe ffic i e nt . ( d)Ha vi ngpl a ye df ort woye ar sands t a yi ngf oronemor eye a ri nt hel e a guer e s ul t si nane ar ni ngsi nc r e as e of7. 8pe r c e nt ,whi l es t a yi ngf oranaddi t i onalye a raf t e r12ye ar si nt hema j or sr e s ul t si napr e di c t e d de c r e as eof25. 3pe r c e nt . ( e )F7, 01a tt he5% l e ve l .He nc eyouc annotr e j e c tt henul lhypot he s i sofe qual i t yofc oe ffic i e nt s ∞ =2. ac r os sl e a gue s . 23 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 8)Af t e ranal yzi ngt hea ge e ar ni ngspr ofil ef or1, 744wor ke r sass howni nt hefigur e ,i tbe c ome sc l e art o yout ha tt her e l a t i ons hi pc annotbeappr oxi ma t e l yl i ne ar . Youe s t i ma t et hef ol l owi ngpol ynomi alr e gr e s s i onmode l ,c ont r ol l i ngf ort hee ffe c tofge nde rbyus i nga bi nar yvar i abl et ha tt ake sont heval ueofonef orf e mal e sandi sze r oot he r wi s e : 2+0. 3–0. 4 =–795. 90+82. 93×Ag e–1. 69×Ag e 015×Ag e 0005×Ag e ( 283. 11)( 29. 29) ( 1. 06) ( 0. 016) ( 0. 0009) –163. 19Fe ma l e ,R2=0. 225,SER=259. 78 ( 12. 45) 4c ( a)Te s tf ort hes i gni fic anc eoft heAg e oe ffic i e nt .De s c r i bet hege ne r als t r a t e gyt ode t e r mi net he appr opr i a t ede gr e eoft hepol ynomi al . ( b)Your unt wof ur t he rr e gr e s s i ons .Pr e s e ntanar gume ntast owhi c honeyous houl dus ef orf ur t he r anal ys i s . 2+0. 3 =–683. 21+65. 83×Ag e–1. 05×Ag e 005×Ag e 120. 13)( 9. 27) ( 0. 22) ( 0. 002) –163. 23Fe ma l e ,R2=0. 225,SER=259. 73 ( 12. 45) 2 =–344. 88+41. 48×Ag e–0. 45×Ag e ( 51. 58) ( 2. 64) ( 0. 03) –163. 81Fe ma l e ,R2=0. 222,SER=260. 22 ( 12. 47) 24 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( c )Ske t c ht hegr aphoffit t e de ar ni ngsofmal e sa ga i ns ta geofyourpr e f e r r e dr e gr e s s i on.Doe st hi sma ke s e ns e ?Ar eyouc onc e r ne daboutt hene ga t i vec oe ffic i e ntont her e gr e s s i oni nt e r c e pt ?Wha ti st he i mpl i c a t i onf orf e mal ee ar ne r si nt hi ss ampl e ? ( d)Expl ai nhow youwoul dc al c ul a t et hee ffe c tofc hangi nga gebyoneye a rone ar ni ngs ,hol di ngc ons t ant t hege nde rvar i abl e .Fi nal l y ,br i e flyde s c r i behow youwoul dc al c ul a t et hes t andar de r r or soft hee s t i ma t e d e ffe c t . Ans we r : ( a)Thec oe ffic i e nthasat s t a t i s t i cof0. 56andhe nc ei snots t a t i s t i c al l ys i gni fic anta tc onve nt i onall e ve l s . Thes t r a t e gyi sde s c r i be di ns e c t i on6. 2oft het e xt book.Cons i de r i ngfir s tapol ynomi alofde gr e er ,t he c oe ffic i e ntas s oc i a t e dwi t ht hel ar ge s tval ueofri st e s t e df ors i gni fic anc e .Fr om t he r e ,as e que nt i al hypot he s i st e s t i ngpr oc e dur es houl dbef ol l owe d. 3i ( b)Thec oe ffic i e ntofAg e ss t a t i s t i c al l ys i gni fic anta tt he1% l e ve lus i ngaone s i de dhypot he s i s .The pol ynomi alofde gr e et hr e es e e mst he r e f or et heappr opr i a t er e gr e s s i on. ( c ) The r ei sl i t t l edi ffe r e nc ebe t we e nt het wofit sf orval ue sbe t we e nt hea geof25and60.Thei nve r t e dUs hapei swe l lknownt oe xi s tf ora ge e ar ni ngspr ofil e s ,andhe nc et hepl otmake ss e ns e .The r ei sno i nt e r pr e t a t i onf ort hei nt e r c e pt ,s i nc et he r ei snoda t ac l os et ot heor i gi n.Fe mal e se ar ns i gni fic ant l yl e s sa t e ve r ya gel e ve l . ( d)Si nc et hi si sanonl i ne arr e l a t i ons hi p,t hee ffe c twi l lde pe ndont hea gel e ve l .Thi si sde s c r i be di n s e c t i on6. 1oft het e xt book.I ne s s e nc e ,t hepr e di c t e de ar ni ngsval uef oronea gel e ve lhast obec omput e d fir s t .Ne xt ,t hes amehast obedonef ort hea gel e ve lpl usone .Fi nal l yt het woval ue sar edi ffe r e nc e dt ofind t hec hangei ne ar ni ngsas s oc i a t e dwi t ht hea gel e ve l . Fort hepol ynomi alofde gr e e3,t hefir s tt as ki st oc ons i de rt hee s t i ma t e dc hangei ne ar ni ngsas s oc i a t e d 2 2 wi t hac hangei na gebyoneye ar ,s a yf r om 30t o31 .Thi si sgi ve nby△ = 1×( 31-30)+ 2( 31 -30)+ 313-303)or△ = 1+612+27913.Thes t andar de r r oroft hee s t i ma t e de ffe c ti st he ngi ve nf r om 3( SE( △ = 2.A95% c ,whe r eF=[ (1+612+27913)/SE(1+612+27913] onfide nc ei nt e r valf or . t hec hangei nt hee xpe c t e dval ueofe ar ni ngsi s(1+612+27913)±1. 96×SE(1+612+27913) Obvi ous l yt he s ee xpr e s s i onsge tqui t ec ompl i c a t e donc eyougobe yondaquadr a t i c . 9)Ear ni ngsf unc t i onsa t t e mptt ofindt hede t e r mi nant sofe ar ni ngs ,us i ngbot hc ont i nuousandbi nar y var i abl e s .Oneoft hec e nt r alque s t i onsana l yze di nt hi sr e l a t i ons hi pi st her e t ur nst oe duc a t i on. 25 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( a)Col l e c t i ngda t af r om 253i ndi vi dual s ,youe s t i ma t et hef ol l owi ngr e l a t i ons hi p =0. 54+0. 083×Educ ,R2=0. 20,SER=0. 445 ( 0. 14)( 0. 011) whe r eEa r ni sa ve r a gehour l ye ar ni ngsandEduci sye ar sofe duc a t i on. Wha ti st hee ffe c tofanaddi t i onalye arofs c hool i ng?I fyouhadas t r ongbe l i e ft ha tye ar sofhi ghs c hool e duc a t i onwe r edi ffe r e ntf r om c ol l e gee duc a t i on,how woul dyoumodi f yt hee qua t i on?Wha ti fyour t he or ys ugge s t e dt ha tt he r ewasa" di pl omae ffe c t " ? ( b)Your e adi nt hel i t e r a t ur et ha tt he r es houl dal s ober e t ur nst oont he j obt r ai ni ng.Toappr oxi ma t eont he j obt r ai ni ng,r e s e ar c he r sof t e nus et hes oc al l e dMi nc e rorpot e nt i ale xpe r i e nc evar i abl e ,whi c hi s de fine dasExpe r=Ag e–Educ–6.Expl ai nt her e as oni ngbe hi ndt hi sappr oxi ma t i on.I si tl i ke l yt o r e s e mbl eye ar sofe mpl oyme ntf orvar i ouss ubgr oupsoft hel aborf or c e ? ( c )Youi nc or por a t et hee xpe r i e nc evar i abl ei nt oyouror i gi nalr e gr e s s i on 2, =0. 01+0. 101×Educ+0. 033×Expe r–0. 0005×Expe r ( 0. 16)( 0. 012) ( 0. 006) ( 0. 0001) R2=0. 34,SER=0. 405 Wha ti st hee ffe c tofanaddi t i onalye arofe xpe r i e nc ef orape r s onwhoi s40ye ar sol dandhad12ye ar sof e duc a t i on?Wha taboutf orape r s onwhoi s60ye ar sol dwi t ht hes amee duc a t i onbac kgr ound? ( d)Te s tf ort hes i gni fic anc eofe ac hoft hec oe ffic i e nt soft headde dvar i abl e s .Whyhast hec oe ffic i e nton e duc a t i onc hange ds ol i t t l e ?Ske t c ht hea ge ( l og) e a r ni ngspr ofil ef orwor ke r swi t h8ye ar sofe duc a t i onand 16ye ar sofe duc a t i on. ( e )Youwantt ofindt hee ffe c tofi nt r oduc i ngt wovar i abl e s ,ge nde randmar i t als t a t us .Ac c or di ngl yyou s pe c i f yabi nar yvar i abl et ha tt a ke sont heval ueofonef orf e mal e sandi sze r oot he r wi s e( Fe ma l e ) ,and anot he rbi nar yvar i abl et ha ti sonei ft hewor ke ri smar r i e dbuti sze r oot he r wi s e( Ma r r i e d) .Addi ngt he s e var i abl e st ot her e gr e s s or sr e s ul t si n: 2 =0. 21+0. 093×Educ+0. 032×Expe r–0. 0005×Expe r ( 0. 16)( 0. 012) ( 0. 006) ( 0. 0001) -0. 289×Fe ma l e+0. 062Ma r r i e d, ( 0. 049) ( 0. 056) R2=0. 43,SER=0. 378 Ar et hec oe ffic i e nt soft het woadde dbi nar yvar i abl e si ndi vi dual l ys t a t i s t i c al l ys i gni fic ant ?Ar et he y e c onomi c al l yi mpor t ant ?I npe r c e nt a get e r ms ,how muc hl e s sdof e mal e se ar npe rhour ,c ont r ol l i ngf or e duc a t i onande xpe r i e nc e ?How muc hmor edomar r i e dpe opl emake ?Wha ti st hepe r c e nt a gedi ffe r e nc e i ne ar ni ngsbe t we e nas i ngl emal eandamar r i e df e mal e ?Wha ti st hemar r i a gedi ffe r e nt i albe t we e nmal e s andf e mal e s ? 26 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( f )I nyourfinals pe c i fic a t i on,youal l ow f ort hebi nar yvar i abl e st oi nt e r a c t .Ther e s ul t sar easf ol l ows : 2 =0. 14+0. 093×Educ+0. 032×Expe r–0. 0005×Expe r ( 0. 16)( 0. 011) ( 0. 006) ( 0. 001) -0. 158×Fe ma l e+0. 173×Ma r r i e d–0. 218×( Fe ma l e×Ma r r i e d) , ( 0. 075) ( 0. 080) ( 0. 097) R2=0. 44,SER=0. 375 Re pe a tt hee x e r c i s ei n( e )ofc al c ul a t i ngt hevar i ouspe r c e nt a gedi ffe r e nc e sbe t we e nge nde randmar i t al s t a t us . Ans we r : ( a)Oneaddi t i onalye a rofe duc a t i onc ar r i e san8. 3pe r c e nti nc r e as e ,orar e t ur n,one ar ni ngs .Youwoul d ne e daddi t i onalda t at os e ei ft hi sc oe ffic i e ntwasdi ffe r e ntf orhi ghs c hoolve r s usc ol l e gee duc a t i on. I nc l udi ngbot hvar i abl e si nt her e gr e s s i onwoul dt he nal l ow yout ot e s tf ore qual i t yoft hec oe ffic i e nt s .A " di pl omae ffe c t "c oul dbes t udi e dbyc r e a t i ngabi na r yvar i abl ef orahi ghs c hooldi pl oma ,aj uni orc ol l e ge di pl oma ,aB. A.orB. Sc .di pl oma ,ands of or t h. ( b)Thei de ai st ha te ve r ybodywor kse x c e pti nt hefir s ts i xye ar sofl i f eanddur i ngt het i mes pe nti n s c hool /uni ve r s i t yf ore duc a t i on.Thi sappr oxi ma t i onwi l lwor kbe t t e rf orpe opl ewi t has t r onga t t ac hme nt t ot hel aborf or c e .I twi l lnotwor kwe l lf orf e mal e sandt hos ewhoar ef r e que nt l yune mpl oye doroutoft he wor kf or c e . ( c )Fort hefir s tpe r s on,t heExpe rvar i abl ei nc r e as e sf r om 22t o23,andr e s ul t si na1. 1pe r c e nte ar ni ngs i nc r e as e .Fort he60ye arol d,t he r ei sane xpe c t e dde c r e as eof1pe r c e nt . ( d)Bot hc oe ffic i e nt sar ehi ghl ys i gni fic antus i ngc onve nt i onall e ve l sofs i gni fic anc e .Thef ac tt ha tt he c oe ffic i e ntont hee duc a t i onvar i abl ehar dl yc hange ds ugge s t st ha te duc a t i onande xpe r i e nc ear enot hi ghl yc or r e l a t e d. 27 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 ( e )Thec oe ffic i e ntf ort hef e mal ebi nar yvar i abl ei ss t a t i s t i c al l ys i gni fic ante ve na tt he1% l e ve l .The c oe ffic i e ntf ort hemar r i e dbi nar yvar i abl eonl yhasat s t a t i s t i cof1. 11andi snots t a t i s t i c al l ys i gni fic anta t t he10% l e ve l .Bot hc oe ffic i e nt si ndi c a t ee c onomi ci mpor t anc e ,s i nc ef e mal e smakeappr oxi ma t e l y29 pe r c e ntl e s st hanmal e sandmar r i e dpe opl ee ar nr oughl y6pe r c e ntmor e .Amar r i e df e mal ee ar nsr oughl y 23pe r c e ntl e s st hanas i ngl emal e .Mar r i e df e mal e se ar n29pe r c e ntl e s st hanmar r i e dmal e s ,t hes ame pe r c e nt a get ha ts i ngl ef e mal e se ar nl e s st hans i ngl emal e s . ( f )Thede f aul ti st hes i ngl emal e .Si ngl ef e mal e se ar n15. 8pe r c e ntl e s s .Mar r i e dmal e se ar n17. 3pe r c e nt mor e .Mar r i e df e mal e se ar n20. 3pe r c e ntl e s s .Compa r i ngmar r i e df e mal e swi t hmar r i e dmal e snow r e s ul t si nape r c e nt a gedi ffe r e nt i alof37. 6pe r c e nti nf a voroft hemal e s . 10)Oneoft hemos tf r e que nt l ye s t i ma t e de qua t i onsi nt hemac r oe c onomi c sgr owt hl i t e r a t ur ear es oc al l e d c onve r ge nc er e gr e s s i ons .I ne s s e nc et hea ve r a gepe rc api t ai nc omegr owt hr a t ei sr e gr e s s e dont he be gi nni ngof pe r i odpe rc api t ai nc omel e ve lt os e ei fc ount r i e st ha twe r ef ur t he rbe hi ndi ni t i al l y ,gr e w f as t e r .Somemac r oe c onomi cmode l smaket hi spr e di c t i on,onc eot he rvar i abl e sar ec ont r ol l e df or .To i nve s t i ga t et hi sma t t e r ,youc ol l e c tda t af r om 104c ount r i e sf ort hes ampl epe r i od19601990ande s t i ma t e t hef ol l owi ngr e l a t i ons hi p( numbe r si npar e nt he s e sar ef orhe t e r os ke das t i c i t yr obus ts t andar de r r or s ) : =0. 020–0. 360×gpo p+0. 004×Educ–0. 053×Re l Pr o d60,R2=0. 332,SER=0. 013 ( 0. 009)( 0. 241) ( 0. 001) ( 0. 009) whe r eg6090i st hegr owt hr a t eofGDPpe rwor ke rf ort he19601990s ampl epe r i od,Re l Pr o d60i st hei ni t i al s t ar t i ngl e ve lofGDPpe rwor ke rr e l a t i vet ot heUni t e dSt a t e si n1960,gpo pi st hea ve r a gepopul a t i on gr owt hr a t eoft hec ount r y ,andEduci se duc a t i onala t t ai nme nti nye ar sf or1985. ( a)Wha ti st hee ffe c tofani nc r e as eof5ye ar si ne duc a t i onala t t ai nme nt ?Wha twoul dhappe ni fac ount r y c oul di mpl e me ntpol i c i e st oc utpopul a t i ongr owt hbyonepe r c e nt ?Ar eal lc oe ffic i e nt ss i gni fic anta tt he 5% l e ve l ?I foneoft hec oe ffic i e nt si snots i gni fic ant ,s houl dyouaut oma t i c al l ye l i mi na t ei t svar i abl ef r om t hel i s tofe xpl ana t or yvar i abl e s ? ( b)Thec oe ffic i e ntont hei ni t i alc ondi t i onhast obes i gni fic ant l yne ga t i vet os ugge s tc ondi t i onal c onve r ge nc e .Fur t he r mor e ,t hel ar ge rt hi sc oe ffic i e nt ,i nabs ol ut et e r ms ,t hef as t e rt hec onve r ge nc ewi l l t akepl ac e .I thasbe e ns ugge s t e dt oyout oi nt e r ac te duc a t i onwi t ht hei ni t i alc ondi t i on t ot e s tf or addi t i onale ffe c t sofe duc a t i onongr owt h.Tot e s tf ort hi spos s i bi l i t y ,youe s t i ma t et hef ol l owi ng r e gr e s s i on: =0. 015-0. 323×gpo p+0. 005×Educ–0. 051×Re l Pr o d60 ( 0. 009)( 0. 238) ( 0. 001) ( 0. 013) –0. 0028×( Educ Re l Pr o d60) ,R2=0. 346,SER=0. 013 ( 0. 0015) 28 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 Wr i t edownt hee ffe c tofanaddi t i onalye a rofe duc a t i onongr owt h.We s tGe r manyhasaval uef or Re l Pr o d60of0. 57,whi l eBr azi l ' sval uei s0. 23.Wha ti st hepr e di c t e dgr owt hr a t ee ffe c tofaddi ngoneye a r ofe duc a t i oni nbot hc ount r i e s ?Doe st hi spr e di c t e dgr owt hr a t emakes e ns e ? ( c )Wha ti st hei mpl i c a t i onf ort hes pe e dofc onve r ge nc e ?I st hei nt e r a c t i one ffe c ts t a t i s t i c al l ys i gni fic ant ? ( d)Conve r ge nc er e gr e s s i onsar ebas i c al l yoft het ype Δl nYt=β nY0 0–β 1l whe r e△ mi ghtbet hec hangeove ral onge rt i mepe r i od,30ye ar s ,s a y ,andt hea ve r a gegr owt hr a t ei sus e d ont hel e f t hands i de .Younot et ha tt hee qua t i onc anber e wr i t t e nas △l nYt=β 1–β nY0 0–( 1)l Ove rac e nt ur ya go,Si rFr anc i sGal t onfir s tc oi ne dt het e r m" r e gr e s s i on"byana l yzi ngt her e l a t i ons hi p be t we e nt hehe i ghtofc hi l dr e nandt hehe i ghtoft he i rpar e nt s .Es t i ma t i ngaf unc t i onoft het ypeabove ,he f oundapos i t i vei nt e r c e ptandas l opebe t we e nze r oandone .Het he r e f or ec onc l ude dt ha the i ght swoul d r e ve r tt ot heme an.Si nc eul t i ma t e l yt hi swoul di mpl yt hehe i ghtoft hepopul a t i onbe i ngt hes ame ,hi s r e s ul thasbe c omeknownas" Gal t on' sFal l ac y . "Youre s t i ma t eofβ sappr oxi ma t e l y0. 05.Doyou 1abovei s e eapar al l e lt oGal t on' sFal l ac y? Ans we r : ( a)I nc r e as i nge duc a t i onala t t ai nme ntby5ye ar sr e s ul t si nani nc r e as eofpr oduc t i vi t ygr owt hof2pe r c e nt . De c r e as i ngt hepopul a t i ongr owt hr a t ebyonepe r c e nti nc r e as e spr oduc t i vi t ygr owt hby0. 4pe r c e nt .Al l c oe ffic i e nt sar es t a t i s t i c al l ys i gni fic anta tt he5% l e ve lwi t ht hee x c e pt i onofpopul a t i ongr owt h.Yous houl d note l i mi na t eavar i abl es i mpl ybe c aus ei ti snots t a t i s t i c al l ys i gni fic ant .I ti sbe t t e rt or e por tt hes t a t i s t i c s andl e tt her e ade rde c i de . ( b) =0. 005-0. 0028Re l Pr o d60.ForWe s tGe r many ,t hee ffe c ti s0. 3pe r c e nt ,whi l ef orBr azi li ti s0. 4 pe r c e nt .The s ear es mal lgai ns ,butt he yac c umul a t eove rt i me . ( c ) =0. 051-0. 0028Educ ,whi c ht he r e f or ede pe ndsone duc a t i onala t t ai nme nt .Count r i e swi t h hi ghe re duc a t i onala t t ai nme ntwi l lc onve r gef as t e r . Thec oe ffic i e nthasat s t a t i s t i cof1. 87andi st he r e f or e s t a t i s t i c al l ys i gni fic anta tt he5% l e ve lus i ngaone s i de dhypot he s i st e s t . ( d)Theabover e gr e s s i onsge ne r a t eame anr e ve r s i onout c ome .I nt e r pr e t e dl i t e r al l y ,t hei mpl i c a t i oni st ha t al lc ount r i e se ndupwi t ht hes amepr oduc t i vi t yorpe rc api t ai nc ome ,j us tasal lpe r s onswoul dbeoft he s amehe i ght .I tc anbes hownt ha tGal t on' sFal l ac yi st her e s ul tofe r r or s i nvar i abl e swhi c hbi as e st he s l opec oe ffic i e ntdownwar d.Thi st opi ci sc ove r e di nCha pt e r7.Thes ol ut i oni st ous ei ns t r ume nt al var i abl et e c hni que s ,al s odi s c us s e di nCha pt e r10. Thel i t e r a t ur ei nt hi sar e ahasdones o,andt he c onve r ge nc er e s ul tpe r s i s t s . 29 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 11)Pa ge s283284i nyourt e xt bookc ont ai nananal ys i soft he" Re t ur nt oEduc a t i onandt heGe nde rGap. " Col umn( 4)i nTabl e8. 1di s pl a ysr e gr e s s i onr e s ul t sus i ngt he2009Cur r e ntPopul a t i onSur ve y .The e qua t i onbe l ow s howst her e gr e s s i onr e s ul tf ort hes ames pe c i fic a t i on,butus i ngt he2005Cur r e nt Popul a t i onSur ve y .I nt e r pr e tt hema j orr e s ul t s . =1. 215+0. 0899×e duc-0. 521×DFe mme +0. 0180×( DFe mme ×e duc ) ( 0. 018)( 0. 0011) ( 0. 022) ( 0. 0016) 2-0. +0. 0232×e xpe r-0. 000368×e xpe r 058×Mi d we s t-0. 0098×So ut h-0. 030×We s t ( 0. 0008) ( 0. 000018) ( 0. 006) ( 0. 0078) ( 0. 0030) Ans we r :Ther e t ur nt oe duc a t i onf ormal e si sappr oxi ma t e l y9% andi t sc oe ffic i e nthasat s t a t i s t i cof11. 25. Forf e mal e s ,t her e t ur ni ss l i ght l yhi ghe r ,appr oxi ma t e l y11%.Si nc et hebi nar yvar i abl ef orf e mal e si s i nt e r ac t e dwi t ht henumbe rofye ar sofe duc a t i on,t hege nde rgapde pe ndsont henumbe rofye ar sof e duc a t i on.Fort het ypi c alhi ghs c hoolgr adua t e( 12ye ar sofe duc a t i on) ,t hege nde rgapi sappr oxi ma t e l y 27%,whi l ef ort het ypi c alc ol l e gegr adua t e( 16ye ar sofe duc a t i on)t hege nde rgapnar r owst o19%.The pot e nt i ale xpe r i e nc evar i abl ee nt e r si nani nve r t e dUs hape ,whi c hi st obee xpe c t e dgi ve nt hes hapeof a ge e ar ni ngspr ofil e sandt hef ac tt ha tpot e nt i ale xpe r i e nc ede pe ndsont hea geoft hei ndi vi dual .The r ei s ade c l i ni ngmar gi nalval uef ore ac hye arofpot e nt i ale xpe r i e nc eunt i li te ve nt ual l ybe c ome sne ga t i ve . No r t he a s ti st heomi t t e dr e gi on,andal lot he rr e gi onsha vel owe r( l og)e ar ni ngs ,r angi ngf r om 0. 8% i nt he So ut ht o5. 8% i nt heMi d we s t .Al lc oe ffic i e nt sar es t a t i s t i c al l ys i gni fic ant . 30 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 8. 3 Ma t he ma t i c alandGr aphi c alPr obl e ms 1)Gi vea tl e as tt hr e ee xampl e sf r om e c onomi c swhe r eyoue xpe c ts omenonl i ne ar i t yi nt her e l a t i ons hi p be t we e nvar i abl e s .I nt e r pr e tt hes l opei ne ac hc as e . Ans we r :Ans we r swi l lvar ybys t ude nt .Typi c alans we r si nvol vet heCobbDougl aspr oduc t i onf unc t i on, t hePhi l l i psc ur ve ,e ar ni ngsf unc t i ons ,and( gi ve nt het e xt bookdi s c us s i on)s t ude ntpe r f or manc eand i nc ome . 2)Sugge s tat r ans f or ma t i oni nt hevar i abl e st ha twi l ll i ne ar i zet hede t e r mi ni s t i cpar toft hepopul a t i on r e gr e s s i onf unc t i onsbe l ow.Wr i t et her e s ul t i ngr e gr e s s i onf unc t i oni naf or mt ha tc anbee s t i ma t e dby us i ngOLS. ( a)Yi=β 0 ( b)Yi= ( c )Yi= ( d)Yi=β 0 Ans we r :( a)l n( Yi )=l n(β n( X1i )+ β n( X2i ) 0)+ β 1l 2l ( b) =β 0 ( c )l n +β 1 =β 0+β 1Xi ( d)l n( Yi )=l n(β n( X1i )+β 0)+β 1l 2X2i 3)I ndi c a t ewhe t he rornotyouc anl i ne ar i zet her e gr e s s i onf unc t i onsbe l ow s ot ha tOLSe s t i ma t i on me t hodsc anbeappl i e d: ( a)Yi= ( b)Yi= +ui Ans we r : ( a)Thef unc t i onc anbel i ne ar i ze dbyt aki ngl ogsonbot hs i de s . ( b)Thef unc t i onc annotbel i ne ar i ze dduet ot headdi t i vee r r ort e r m. 31 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 4)Choos ea tl e as tt hr e edi ffe r e ntnonl i ne arf unc t i onalf or msofas i ngl ei nde pe nde ntvar i abl eands ke t c h t her e l a t i ons hi pbe t we e nt hede pe nde ntandi nde pe nde ntvar i abl e . Ans we r :Ans we r swi l lvar ybys t ude nt .Mos tc ommonl yus e df or msar et hequadr a t i cr e gr e s s i on,t he i nve r s e( i nX)r e gr e s s i on,andt hel ogl ogmode l . 32 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 5)I nt hec as eofpe r f e c tmul t i c ol l i ne ar i t y ,OLSi sunabl et oe s t i ma t et hes l opec oe ffic i e nt soft hevar i abl e s i nvol ve d.As s umet ha tyouha vei nc l ude dbot hX1andX2ase xpl ana t or yvar i abl e s ,andt ha tX2=X ,s o t ha tt he r ei sane xa c tr e l a t i ons hi pbe t we e nt woe xpl ana t or yvar i abl e s .Doe st hi spos eapr obl e mf or e s t i ma t i on? Ans we r :The r ei snopr obl e mf ore s t i ma t i on,s i nc et hes e c onde xpl ana t or yvar i abl ei snotl i ne ar l yr e l a t e d t ot hefir s t . Thi si sane xampl eofapol ynomi alr e gr e s s i onmode lofde gr e e2,whi c hi sf r e que nt l y e s t i ma t e di ne c onome t r i c s 33 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 6)Thefigur es howsi sapl otandafit t e dl i ne arr e gr e s s i onl i neoft hea ge e ar ni ngspr ofil eof1, 744 i ndi vi dual s ,t ake nf r om t heCur r e ntPopul a t i onSur ve y . ( a)De s c r i bet hepr obl e msi npr e di c t i nge ar ni ngsus i ngt hefit t e dl i ne .Wha twoul dt hepa t t e r noft he r e s i dual sl ookl i kef ort hea gec a t e gor yunde r40? ( b)Wha tal t e r na t i vef unc t i onalf or m mi ghtfitt heda t abe t t e r ? ( c )Wha tot he rvar i abl e smi ghtyouwantt oc ons i de ri ns pe c i f yi ngt hede t e r mi nant sofe ar ni ngs ? Ans we r : ( a)The r ewoul dbemanyove r pr e di c t i onsf ort hi sa gec a t e gor yunde r40,andhe nc emor ene ga t i ve r e s i dual s . ( b)I twoul dbebe t t e rt ofitaquadr a t i che r e ,i . e . ,apol ynomi alr e gr e s s i onmode l ,whi c hwoul dpr oduc ean i nve r t e dUs hape . ( c )Ans we r swi l lvar ybys t ude nt s ,bute duc a t i on,ge nde r ,r ac e ,t e nur ewi t hane mpl oye r ,pr of e s s i onal c hoi c e ,andabi l i t yar et ypi c al l ypr e s e nti nans we r s . 7)( Re qui r e sCal c ul us )Show t ha tf ort hel ogl ogmode lt hes l opec oe ffic i e nti st hee l as t i c i t y . Ans we r :Cons i de rt hede t e r mi ni s t i cpar tY=AXβ nl n( Y)=β n( X) ,whe r eβ n( A) .Now 1.The 0+β 1l 0=l 1 Y Y X Y Y =β .Al t e r na t i ve l yyouc ande r i vet hes amer e s ul tbyt aki ngt hede r i va t i ve 1= 1 X X X Y Y f r om Y=AXβ 1. 8)As s umet ha tyouhadda t af orac r os s s e c t i onof100hous e hol dswi t hda t aonc ons umpt i onand pe r s onaldi s pos abl ei nc ome .I fyoufital i ne arr e gr e s s i onf unc t i onr e gr e s s i ngc ons umpt i onondi s pos abl e i nc ome ,wha tpr i ore xpe c t a t i onsdoyouha veaboutt hes l opeandt hei nt e r c e pt ?Thes l opeoft hi s r e gr e s s i onf unc t i oni sc al l e dt he" mar gi nalpr ope ns i t yt oc ons ume . "I f ,i ns t e ad,youfital ogl ogmode l , t he nwha ti st hei nt e r pr e t a t i onoft hes l ope ?Doyouha veanypr i ore xpe c t a t i onabouti t ss i ze ? Ans we r :Fort hel ogl ogs pe c i fic a t i on,t hes l opei st hee l as t i c i t y .Si nc et he r ear emanyt he or i e st ha tpr e di c t ac ons t anta ve r a gepr ope ns i t yt oc ons ume ,t hee l as t i c i t ys houl de qualone . 34 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 9)Thet e xt books howst ha tl n( x+Δx)–l n( x)≅ .Show t ha tt hi si se qui val e ntt ot hef ol l owi ng appr oxi ma t i on l n( 1+y)≅ yi fyi ss mal l .Youus et hi si de at oe s t i ma t eade mandf ormone yf unc t i on, u whi c hi soft hef or m m =β ×, ×e whe r emi st hequant i t yof( r e al )mone y ,GDPi st he 0× val ueof( r e al )Gr os sDome s t i cPr oduc t ,andRi st henomi nali nt e r e s tr a t e .Youc ol l e c tt hequar t e r l yda t a f r om t heFe de r alRe s e r veBankofSt .Loui sda t abank( " FRED" ) ,whi c hl i s t st hemone ys uppl yandGDPi n bi l l i onsofdol l ar s ,pr i c e sasani nde x ,andnomi nali nt e r e s tr a t e si npe r c e nt a gepoi nt spe rye ar Youge ne r a t et hevar i abl e si nyourr e gr e s s i onpr ogr am asf ol l ows :m =( mone ys uppl y) /pr i c ei nde x ;GDP =( Gr os sDome s t i cPr oduc t /Pr i c eI nde x) ,andR=nomi nali nt e r e s tr a t ei npe r c e nt a gepoi nt spe rannum. Ne xtyoupe r f or mt hel ogt r ans f or ma t i onsont her e almone ys uppl y ,r e alGDP,andon( 1+R) .Canyouf or s e eapr obl e mi nus i ngt hi st r ans f or ma t i on? Ans we r :l n( x+△x)-l n( x)=l n =l n =l n( 1+y) ,whe r ey= .Le ty=0. 05,t he nl n( 1+y)= 0. 049≈ 0. 05.Not et ha tt hi sappr oxi ma t i ondoe snothol dwe l lf orl ar ge rf r ac t i ons ,s uc has0. 60.The i nt e r e s tr a t ei sl i s t e di npe r c e nt a gepoi nt s .Ent e r i ngRas5,r a t he rt han0. 05,make sβ qualas e mi 2note e l as t i c i t y . 10)Youha vee s t i ma t e dane ar ni ngsf unc t i on,whe r eyour e gr e s s e dt hel ogofe ar ni ngsonas e tof c ont i nuouse xpl ana t or yvar i abl e s( i nl e ve l s )andt wobi nar yvar i abl e s ,onef orge nde randt heot he rf or mar i t als t a t us .Oneoft hee xpl ana t or yvar i abl e si se duc a t i on. ( a)I nt e r pr e tt hee duc a t i onc oe ffic i e nt . ( b)Ne xt ,s pe c i f yt hebi nar yvar i abl e sandane qua t i on,whe r et hede f aul ti sas i ngl emal e ,wi t hout al l owi ngf ori nt e r a c t i onbe t we e nmar i t als t a t usandge nde r .I ndi c a t et hec oe ffic i e nt st ha tme as ur et he e ffe c tofas i ngl emal e ,s i ngl ef e mal e ,mar r i e dmal e ,andmar r i e df e mal e . ( c )Fi nal l yal l ow f orani nt e r ac t i onbe t we e nt hege nde randmar i t als t a t usbi nar yvar i abl e s .Re pe a tt he e x e r c i s eofwr i t i ngdownt hevar i ouse ffe c t sbas e dont hef e mal e /mal eands i ngl e /mar r i e ds t a t us .Whyi s t hel a t t e rappr oac hmor ege ne r alt hant hef or me r ? Ans we r : ( a)Thec oe ffic i e ntone duc a t i ongi ve syout her e t ur nt oe duc a t i on,i . e . ,i fe duc a t i oni nc r e as e dbyoneye ar , t he nbyhow manype r c e ntdoe ar ni ngsi nc r e as e ? ( b)Le tDGe nde re qualonei ft hei ndi vi duali saf e mal e ,andbez e r oot he r wi s e .DMa r r i e dt ake sonaval ue ofonei ft hei ndi vi duali smar r i e dandi sze r oot he r wi s e .Ther e gr e s s i oni s = 0+ 1DGe nde r+ 2DMa r r i e d+. . . Si ngl emal e :0;s i ngl ef e mal e :0+ 1;mar r i e dmal e :0+ 2;mar r i e df e mal e :0+ 1+ 2. = 0+ 1DGe nde r+ 2DMa r r i e d+ 3( DGe nde r×DMa r r i e d+. . . Si ngl emal e :0;s i ngl ef e mal e :0+ 1;mar r i e dmal e :0+ 2;mar r i e df e mal e :0+ 1+ 2+ 3.Thi s appr oac hi smor ege ne r albe c aus ei tal l owst hee ffe c tofbe i ngmar r i e dandf e mal et obedi ffe r e ntf r om be i ngmar r i e dandmal e .I n( b) ,bot hf e mal e sandmal e swe r ef a c e dwi t hi de nt i c ale ffe c t sf r om be i ng mar r i e d,2.I n( c ) ,t hi se ffe c tdi ffe r sduet ot headdi t i onalc oe ffic i e nt 3. ( c ) 35 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 11)Youha vebe e nt ol dt ha tt hemone yde mandf unc t i oni nt heUni t e dSt a t e shasbe e nuns t abl es i nc et he l a t e1970.Toi nve s t i ga t et hi spr obl e m,youc ol l e c tda t aont her e almone ys uppl y( m=M/P;whe r eM i sM1 andPi st heGDPde fla t or ) ,( r e al )gr os sdome s t i cpr oduc t( GDP)andt henomi nali nt e r e s tr a t e( R) .Ne xt youc ons i de re s t i ma t i ngt hede mandf ormone yus i ngt hef ol l owi ngal t e r na t i vef unc t i onalf or ms : ( i )m=β 0+β 1×GDP+β 2xR+u u ( i i )m =β x ×e 0× ( i i i )m=β 0× x u ×e Gi veani nt e r pr e t a t i onf orβ ne ac hc as e .How woul dyouc al c ul a t et hei nc omee l as t i c i t yi nc as e 1andβ 2i ( i ) ? Ans we r :I n( i ) ,bot hc oe ffic i e nt ss how t hee ffe c tofauni ti nc r e as eoft her e s pe c t i vevar i abl e sont he de mandf ormone y .I n( i i ) ,t het woc oe ffic i e nt sar ee l as t i c i t i e s .I n( i i i ) ,1i sane l as t i c i t y ,whe r e as 2i sof t e n r e f e r r e dt oasa" s e mi e l as t i c i t y . "Thes pe c i fic a t i onbe c ome sl n( m)=l n(0)+ 1l n( GDP)+ 2R+u,s i nc e l n( 1+R)≈ Rf ors mal lR.He nc e 2= ,t ha ti s ,i ti ndi c a t e sbyhow manype r c e ntt he( r e al )mone y de mandwi l li nc r e as ef orape r c e nt a gec hangei nt hei nt e r e s tr a t e . 12)Youha vec ol l e c t e dda t af orac r os s s e c t i onofc ount r i e si nt wot i mepe r i ods ,1960and1997,s a y .Your t as ki st ofindt hede t e r mi nant sf ort heWe al t hofaNa t i on( pe rc api t ai nc ome )andyoube l i e vet ha tt he r e ar et hr e ema j orde t e r mi nant s :i nve s t me nti nphys i c alc api t ali nbot ht i mepe r i ods( X1, a n d X ) , T 1, 0 i nve s t me nti nhumanc api t alore duc a t i on( X2, ,andpe rc api t ai nc omei nt hei ni t i alpe r i od TandX2, 0) ( Y0) .Your unt hef ol l owi ngr e gr e s s i on: l n( YT)=β n( Y0)+uT 0+β 1X1, T+β 2X1, 0+β 3X2, T+β 4X1, 0+l Oneofyourpe e r ss ugge s t st ha ti ns t e ad, yous houl dr unt hegr owt hr a t ei npe rc api t ai nc omeove rt het wo pe r i odsont hec hangei nphys i c alandhumanc api t al .Fort hos er e s ul t st obeapar s i moni ouspr e s e nt a t i on ofyouri ni t i alr e gr e s s i on,wha tt hr e er e s t r i c t i onswoul dha vet ohol d?How woul dyout e s tf ort he s e ?The s amepe r s onal s opoi nt soutt oyout ha tt hei nt e r c e ptvani s he si ne qua t i onswhe r et heda t ai sdi ffe r e nc e d. I st ha tt r ue ? Ans we r :Ther e gr e s s i onus i nggr owt hr a t e si sasf ol l ows : [ l n( YT)-l n( Y0) ]= β X1, +β X2, +(β n( Y0)+uT 0+β 1( T-X1, 0) 3( T-X1, 0) 5-1)l Fort hi st obeapar s i moni ouspr e s e nt a t i onoft hei ni t i alr e gr e s s i on,t hef ol l owi ngt wor e s t r i c t i onsmus t hol d:β = β , a n d β = β . T h e u s e o f a n F t e s t i s r e q u i r e d h e r e t o t e s t t h e r e s t r i c t i o n s s i mu l t a n e o u s l y . The 1 2 3 4 i nt e r c e pti ss t i l lpr e s e nti nt hee qua t i on,andt heas s e r t i ont he r e f or ec annotbet r ue . 36 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 13)Ear ni ngsf unc t i onsa t t e mptt opr e di c tt hel ogofe ar ni ngsf r om as e tofe xpl ana t or yvar i abl e s ,bot h bi nar yandc ont i nuous .Youha veal l owe df orani nt e r a c t i onbe t we e nt woc ont i nuousvar i abl e s :e duc a t i on andt e nur ewi t ht hec ur r e nte mpl oye r .Youre s t i ma t e de qua t i oni soft hef ol l owi ngt ype : = 0+ 1×Fe mme+ 2×Educ+ 3×Te nur e+ 4x( Educ×Te nur e )+∙ ∙ ∙ whe r eFe mmei sabi nar yvar i abl et aki ngont heval ueofonef orf e mal e sandi sz e r oot he r wi s e ,Educi st he numbe rofye ar sofe duc a t i on,andt e nur ei sc ont i nuousye ar sofwor kwi t ht hec ur r e nte mpl oye r .Wha ti s t hee ffe c tofanaddi t i onalye a rofe duc a t i onone ar ni ngs( " r e t ur nst oe duc a t i on" )f orme n?Forwome n?I f youal l owe df ort her e t ur nst oe duc a t i ont odi ffe rf ormal e sandf e mal e s ,how woul dyour e s pe c i f yt he abovee qua t i on?Wha ti st hee ffe c tofanaddi t i onalye aroft e nur ewi t hac ur r e nte mpl oye rone ar ni ngs ? Ans we r :Forbot hmal e sandf e mal e s ,t hee ffe c tofanaddi t i onalye arofe duc a t i oni s = 2+ 4xTe nur e ,andhe nc ede pe ndsonc ont i nuousye ar sofwor kwi t ht hec ur r e nte mpl oye r . Toal l ow t hee ffe c tt obedi ffe r e ntf ormal e sandf e mal e s ,ani nt e r a c t i onvar i abl ebe t we e nFe mmeandEduc woul dha vet obei nt r oduc e d.Ther e t ur nt ot e nur ewi t hac ur r e nte mpl oye ri s = 3+ 4xEduc . 14)Manyc ount r i e st ha te xpe r i e nc ehype r i nfla t i ondonotha vemar ke t de t e r mi ne di nt e r e s tr a t e s .Asa r e s ul t ,s omeaut hor sha ves ubs t i t ut e df ut ur ei nfla t i onr a t e si nt omone yde mande qua t i onsoft hef ol l owi ng t ypeasapr oxy: ( mi sr e almone y ,andPi st hec ons ume rpr i c ei nde x) . I nc omei st ypi c al l yomi t t e ds i nc emove me nt si ni tar edwar f e dbymone ygr owt handt hei nfla t i onr a t e . Aut hor sha vet he ni nt e r pr e t e dβ he" s e mi e l as t i c i t y"oft hei nfla t i onr a t e .Doyous e eanypr obl e ms 1ast wi t ht hi si nt e r pr e t a t i on? Ans we r :Li ne ar i zi ngt heabovee qua t i onr e s ul t si nl n( m)=l n( β n( 1+Δl nP)+u.Now t hi ss i mpl i fie s 0)+β 1l t ol n( m)=l n( β nP+ui fΔl nP,t hei nfla t i onr a t e ,i ss mal l .I nt ha tc as e ,β e pr e s e nt st hee ffe c tofa 0)+β 1Δl 1r pe r c e nti nc r e as ei nt hei nfla t i onr a t eont hede mandf ormone y .Howe ve r ,i ft hei nfla t i onr a t ei snots mal l , asi st hec as ei nhype r i nfla t i ons ,t he nt heappr oxi ma t i ondoe snothol danyl onge r . 15)Toi nve s t i ga t ewhe t he rornott he r ei sdi s c r i mi na t i ona gai ns tas ubgr oupofi ndi vi dual s ,your e gr e s s t hel ogofe ar ni ngsonde t e r mi ni ngvar i abl e s ,s uc hase duc a t i on,wor ke xpe r i e nc e ,e t c . ,andabi nar y var i abl ewhi c ht ake sont heval ueofonef ori ndi vi dual si nt ha ts ubgr oupandi sze r oot he r wi s e .You c ons i de rt wopos s i bl es pe c i fic a t i ons .Fi r s tyour unt wos e par a t er e gr e s s i ons ,onef ort heobs e r va t i onst ha t i nc l udet hes ubgr oupandonef ort heot he r s .Se c ond,your unas i ngl er e gr e s s i on,butal l ow f orabi nar y var i abl et oappe ari nt her e gr e s s i on.Yourpr of e s s ors ugge s t st ha tt hes e c onde qua t i oni sbe t t e rf ort het as k a thand,asl ongasyoual l ow f oras hi f ti nbot ht hei nt e r c e ptandt hes l ope s .Expl ai nhe rr e as oni ng. Ans we r :Byr unni ngt her e gr e s s i onove rt hee nt i r es ampl epe r i od,youc ant e s tf ore qual i t yofc oe ffic i e nt s , oral t e r na t i ve l y ,f ort hes i gni fic anc eofbi nar yvar i abl e sc oe ffic i e nt s .Al s o,t hec ombi ne ds ampl ehasmor e obs e r va t i ons ,andhe nc es mal l e rs t andar de r r or s . 37 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 16)Be i ngac ompe t i t i vef e mal es wi mme r ,youwonde ri fwome nwi l le ve rbeabl et obe a tt het i meoft he mal egol dme dalwi nne r .Toi nve s t i ga t et hi sque s t i on,youc ol l e c tda t af ort heOl ympi cGame ss i nc e1910. Atfir s tyouc ons i de ri nc l udi ngvar i ousdi s t anc e s ,abi nar yvar i abl ef orMar kSpi t z ,andanot he rbi nar y var i abl ef ort hear r i valandpr e s e nc eofEas tGe r manf e mal es wi mme r s ,buti nt hee ndde c i deonas i mpl e l i ne arr e gr e s s i on.Yourde pe nde ntvar i abl ei st her a t i ooft hef as t e s twome n' st i met ot hef as t e s tme n' st i me i nt he100m bac ks t r oke ,andt hee xpl ana t or yvar i abl ei st heye a roft heOl ympi c s .Ther e gr e s s i onr e s ul ti s asf ol l ows , =4. 42–0. 0017×Ol ympi c s , whe r eTFo v e r Mi st her e l a t i vet i meoft hegol dme dalwi nne r ,andOl ymp i c si st heye a roft heOl ympi c Game s .Wha ti syourpr e di c t i onwhe nf e mal e swi l lc a t c hupt ome ni nt hi sdi s c i pl i ne ?Doe st hi ss ound pl aus i bl e ?Wha tot he rf unc t i onalf or m mi ghtyouwantt oc ons i de r ? Ans we r :Ac c or di ngt ot heabover e gr e s s i on,wome nwi l lc a t c hupi nt heye ar2011. 76or2012.( Thi s happe nst obeanOl ympi c sye ar . )Thi si snotpl aus i bl ef ors wi mmi ng,andabe t t e rf unc t i onalf or m woul d beTFo v e r M =β 0+β 1 . 38 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 17)Ske t c hf ort hel ogl ogmode lwha tt her e l a t i ons hi pbe t we e nYandXl ooksl i kef orvar i ouspar ame t e r val ue soft hes l ope ,i . e . ,β 1) . 1>1;0<β 1<1;β 1=( Ans we r : 39 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 18)Show t ha tf ort hef ol l owi ngr e gr e s s i onmode l Yt= whe r eti sat i met r e nd,whi c ht ake sont heval ue s1,2,…, T,β e pr e s e nt st hei ns t ant ane ous( " c ont i nuous 1r c ompoundi ng" )gr owt hr a t e .Show how t hi sr a t ei sr e l a t e dt ot hepr opor t i ona t er a t eofgr owt h,whi c hi s c al c ul a t e df r om t her e l a t i ons hi p t Yt=Y0×( 1+g) whe nt i mei sme as ur e di ndi s c r e t ei nt e r val s . Ans we r :l n( Yt )=β nc eβ 0+β 1×t+uandhe 1= = t .Fr om Yt=Y0×( 1+g) ,wege tl n( Yt )= l n( Y0)+l n( 1+ g) t=β ,whe r eβ n( Y0)and β 1+g)≈ gf ors mal lg.He nc ei fgi ss mal l ,t he n 0+β 1t 0=l 1=( r e gr e s s i ngt hel ogofavar i abl eont i mege ne r a t e sas l opec oe ffic i e ntwhi c hi sappr oxi ma t e l yt he pr opor t i ona t er a t eofgr owt hf ors mal lgr owt hr a t e s . 19)Yourt as ki st oe s t i ma t et hei c ec r e am s al e sf orac e r t ai nc hai ni nNe w Engl and.Thec ompanymake s a vai l abl et oyouquar t e r l yi c ec r e am s al e s( Y)andi nf or msyout ha tt hepr i c epe rgal l onhasappr oxi ma t e l y r e mai ne dc ons t antove rt hes ampl epe r i od.Youga t he ri nf or ma t i onona ve r a gedai l yt e mpe r a t ur e s( X) dur i ngt he s equar t e r sandr e gr e s sYonX,addi ngs e as onalbi nar yvar i abl e sf ors pr i ng,s umme r ,andf al l . The s evar i abl e sar ec ons t r uc t e dasf ol l ows :DSpr i ngt ake sonaval ueof1dur i ngt hes pr i ngandi sz e r o ot he r wi s e ,DSumme rt ake sonaval ueof1dur i ngt hes umme r ,e t c .Spe c i f yt hr e er e gr e s s i onf unc t i ons whe r et hef ol l owi ngc ondi t i onshol d:t her e l a t i ons hi pbe t we e nYandXi s( i )f or c e dt obet hes amef ore ac h quar t e r ;( i i )al l owe dt oha vedi ffe r e nti nt e r c e pt se ac hs e as on;( i i i )al l owe dt oha vevar yi ngs l ope sand i nt e r c e pt se ac hs e as on.Ske t c ht hedi ffe r e nc ebe t we e n( i )and( i i ) .How woul dyout e s twhi c hmode lfit st he da t at hebe s t ? Ans we r :( i )Yi=β ; 0+β 1Xi+ui ( i i )Yi=β + β X + β D S p r i n g + β r+β l l+ui ; 0 1i 2 3DSumme 4DFa ( i i i )Yi=β i ng+β r+β l l 0+β 1Xi+β 2DSpr 3DSumme 4DFa +β DSpr i ng×Xi )+β DSumme r×Xi)+β DFa l l×Xi )+ui ; 5( 6( 7( ( i i i )i st hemos tge ne r aloft hemode l s ,t heot he r sar ene s t e d.He nc eyouc anus et heFt e s tt os e ei fc e r t ai n r e s t r i c t i onshol d.Fore xampl e ,( i )i sapar s i moni ousr e pr e s e nt a t i onof( i i i )i fal lc oe ffic i e nt si nvol vi ngt he s e as onalbi nar yvar i abl e sar es i mul t ane ous l ye qualt oz e r o. 40 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 20)I ne s t i ma t i ngt heor i gi nalr e l a t i ons hi pbe t we e nmone ywa gegr owt handt heune mpl oyme ntr a t e , Phi l l i psus e dUni t e dKi ngdom da t af r om 1861t o1913t ofitac ur veoft hef ol l owi ngf unc t i onalf or m ( whe r e +β 0)=β 1× u, ×e i st hepe r c e nt a gec hangei nmone ywa ge sanduri st heune mpl oyme ntr a t e .Ske t c ht he f unc t i on.Wha tr ol edoe sβ a y?Canyoufindal i ne art r ans f or ma t i ont ha tal l owsyout oe s t i ma t et he 0pl abovef unc t i onus i ngOLS?I f ,a f t e rt aki ngl ogar i t hmsonbot hs i de soft hee qua t i on,yout r i e dt oe s t i ma t e β a n d β u s i n g O L S b y c h o o s i n g d i ff e r e n t v a l u e s f o r β b y " t r i a l a n d e r r o r p r o c e d u r e " ( P h i l l i p s ' s w o r d s ) , 1 2 0 wha ts or tofpr obl e m mi ghtyour uni nt owi t ht hel e f t hands i devar i abl ef ors omeoft heobs e r va t i ons ? Ans we r :Gi ve nt hes hapeoft hePhi l l i psc ur ve ,β l lbene ga t i veandβ l lbepos i t i ve .He nc ef orl ar ge 2wi 1wi val ue sofβ 1× wi l lbeappr oxi ma t e l yze r o,β st hel owe ras ympt ot eof 0andi onbot hs i de sr e s ul t si nl n( .Taki ngl ogar i t hms +β n( β +β n( ur )+u,whi c hc annotbee s t i ma t e dbyOLSduet ot he 0)=l 1) 2l f or m oft hede pe nde ntvar i abl e .Choos i ngdi ffe r e ntval ue sf orβ anr e s ul ti ns i t ua t i onswhe r e( 0c +β 0) i sne ga t i veandhe nc ei snotde fine d. 21)Us i ngas pr e ads he e tpr ogr am s uc hasEx c e l ,pl ott hef ol l owi ngl ogi s t i cr e gr e s s i onf unc t i onwi t ha s i ngl eX, i= ,whe r e 0=-4. 13and 1=5. 37.Ent e rval ue sofXi nt hefir s tc ol umn s t ar t i ngf r om 0andt he ni nc r e me nt i ngt he s eby0. 1unt i lyour e ac h2. 0.The ne nt e rt hel ogi s t i cf unc t i on f or mul ai nt hene xtc ol umn.Fi nal l ypr oduc eas c a t t e rpl ot ,c onne c t i ngt hepr e di c t e dval ue swi t hal i ne . Ans we r : 41 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 22)Tabl e8. 1onpa ge284ofyourt e xt bookdi s pl a yst hef ol l owi nge s t i ma t e de ar ni ngsf unc t i oni nc ol umn ( 4) : =1. 503+0. 1032×e d uc-0. 451×DFe mme+0. 0143×( DFe mme ×e d uc ) ( 0. 023)( 0. 0012) ( 0. 024) ( 0. 0017) 2-0. +0. 0232×e xpe r-0. 000368×e xpe r 058×Mi d we s t-0. 0098×So ut h-0. 030×We s t ( 0. 0012) ( 0. 000023) ( 0. 006) ( 0. 006) ( 0. 007) n=52. 790, 2=0. 267 Gi ve nt ha tt hepot e nt i ale xpe r i e nc evar i abl e( e xpe r )i sde fine das( Age Educ a t i on6)findt hea gea twhi c h i ndi vi dual swi t hahi ghs c hoolde gr e e( 12ye ar sofe duc a t i on)andwi t hac ol l e gede gr e e( 16ye ar sof e duc a t i on)ha vemaxi mum e ar ni ngs ,hol di ngal lot he rf a c t or sc ons t ant . Ans we r :Theans we rc anbef ounde i t he rbyus i ngc a l c ul usorgr aphi c al /s pr e ads he e tt e c hni que s . Maxi mum e ar ni ngsoc c ur sa tpot e nt i ale xpe r i e nc eof31. 5.He nc ewi t h12ye ar sofe duc a t i on,t he maxi mum e ar ni ngshappe na ta ge49. 5,whi l ef orape r s onwi t h16ye ar sofe duc a t i ont he s eoc c ura t53. 5 ye ar s .( Si nc et aki ngl ogar i t hmsr e s ul t si namonot oni s t i ct r ans f or ma t i onoft heor i gi nalda t a ,t hes ame r e s ul t shol df ort hel ogofe ar ni ngsasf ore ar ni ngs ) . 23)Cons i de rat ypi c alb e t ac o nv e r g e nc er e gr e s s i onf unc t i onf r om mac r oe c onomi c s ,whe r et hegr owt hofa c ount r y' spe rc api t ai nc omei sr e gr e s s e dont hei ni t i all e ve lofpe rc api t ai nc omeandvar i ousot he r e c onomi cands oc i oe c onomi cvar i abl e s .As s umet ha tt wooft he s evar i abl e sar et hea ve r a genumbe rof ye ar sofe duc a t i oni nt hes pe c i ficc ount r yandabi nar yvar i abl ewhi c hi ndi c a t e swhe t he rornott he c ount r ye xpe r i e nc e das i gni fic antnumbe rofye ar sofc i vi lwar /unr e s t .Expl ai nwhyi twoul dmakes e ns e t oha vet he s et wovar i abl e se nt e rs e par a t e l yandal s owhyyous houl dus eani nt e r a c t i ont e r m.Wha ts i gns woul dyoue xpe c tont het hr e ec oe ffic i e nt s ? Ans we r :Si mpl ee xt e ns i onsoft hes t andar dne oc l as s i c algr owt hmode ls ugge s tt ha tt henumbe rofye ar sof e duc a t i onha veapos i t i vee ffe c tonc ondi t i onalgr owt hi nt hewe al t hofana t i on( pe rc api t ai nc ome ) .A c i vi lwarwoul dha veane ga t i vee ffe c tont hei nve s t me nt /out putr a t i o( s a vi ngsr a t e )andyouwoul d t he r e f or ee xpe c tane ga t i ves i gnont hec oe ffic i e nt .Howe ve r ,i ti si mpor t antt oi nt e r ac tt hevar i abl e s be c aus enoma t t e rhow muc he duc a t i ont hea ve r a gepe r s onhas ,t he r ewi l lbevi r t ual l ynoi nve s t me nti na c ount r ydur i ngac i vi lwar .He nc eyouwoul de xpe c tane ga t i ves i gn,whi c hwoul di ndi c a t et hee ffe c tt ha ta c i vi lwarhasont hee duc a t i one ffe c t . 42 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) lOMoARcPSD|27111031 24)Cons i de rt hef ol l owi ngr e gr e s s i onoft e s t s c or e sonani nt e r c e pt ,abi nar yvar i abl et ha te qual s1i ft he s t ude nt t e ac he rr a t i oi s20ormor e( Hi STR)andanot he rbi nar yvar i abl et ha te qual s1i ft hepe r c e nt a geof Engl i s hl e ar ne r si s10% ormor e( Hi EL) . =664/1-1. 9×Hi STR-18. 2×Hi EL-3. 5×( Hi STR×Hi EL) Us i ngt het wobyt wot abl ebe l ow,fil li nt hee xpe c t e dt e s t s c or e sofas t ude ntwi t hvar i ousc ombi na t i onsof t hehi gh/l ow s t ude ntt e ac he rr a t i oandt hehi gh/l ow pe r c e ntofEngl i s hl e ar ne r s . STR<20 STR EL<10% EL 10% Ans we r : EL<10% EL 10% STR<20 664. 1 645. 9 STR 20 662. 2 640. 5 43 Copyr i ght©2011Pe ar s onEduc a t i on,I nc . Downloaded by Qu?nh Nhi Tr?n (quynhnhitran1110@gmail.com) 20