Intr
- duc tion to E
c onome tr ic s
Chapte r 4
E ze quie l Ur ie l Jimé ne z
Unive r sity of Vale nc ia Vale nc ia, Se pte mbe r 2013
Intr oduc tion to E c onome tr ic s Chapte r 4 E ze quie l Ur - - PowerPoint PPT Presentation
Intr oduc tion to E c onome tr ic s Chapte r 4 E ze quie l Ur ie l Jim ne z Unive r sity of Vale nc ia Vale nc ia, Se pte mbe r 2013 4 Hypothe sis te sting in the multiple r e gr e ssion mode l 4.1 Hypothe sis te sting: an ove r
Unive r sity of Vale nc ia Vale nc ia, Se pte mbe r 2013
4.1 Hypothe sis te sting: an ove r vie w 4.2 T e sting hypothe se s using the t te st 4.3 T e sting multiple line ar r e str ic tions using the F te st 4.4 T e sting without nor mality 4.5 Pr e dic tion E xe r c ise s
T e sting hypo the sis c an answe r the fo llo wing que stio ns:
s the marg inal pro pe nsity to c o nsume smalle r than the ave rag e pro pe nsity to c o nsume ?
are a?
s the e lastic ity e xpe nditure in fruit/ inc o me e qual to 1? I s fruit a luxury g o o d?
s the Madrid sto c k e xc hang e marke t e ffic ie nt?
s the rate o f re turn o f the Madrid Sto c k E xc hang e affe c te d by the rate o f re turn o f the T
xc hang e ?
s the assumptio n o f ho mo g e ne ity admissible in the de mand fo r fish?
s the pe rfo rmanc e o f a c o mpany c ruc ial to se t the salarie s o f CE Os? All the se que stio ns are answe re d in this c hapte r
Motivation
[3]
4 Hypothesis testing in the multiple regression model [4]
T ABL E 4.1. Some distr ibutions use d in hypothe sis te sting.
2
2
[5]
F
IGURE 4.1. Hypothe sis te sting: c lassic al appr
4 Hypothesis testing in the multiple regression model
Non Rejection Region NRR Rejection Region RR
W
[6]
F
IGURE 4. 2. De nsity func tions: nor
mal and t for diffe r e nt de gr e e s of fr e e dom.
4 Hypothesis testing in the multiple regression model
[7]
F
IGURE 4.3. Re je c tion r
e gion using
t: r
ight- tail alte r native hypothe sis. F
IGURE 4.4. p-value using t:
r ight- tail alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
[8]
F
IGURE 4.5. E
xample 4.1: Re je c tion r e gion using t with a r ight- tail alte r native hypothe sis. F
IGURE 4.6. E
xample 4.1: p-value using t with r ight- tail alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.1 Is the mar ginal pr
than the ave r age pr
(0.350) (0.062)
0.41 0.843
i i
cons inc = +
1 2
cons inc u
1 1 1
: : H H
1 1 1 1 1
ˆ ˆ 0.41 1.171 ˆ ˆ 0.35 ( ) ( ) t se se
[9]
F
IGURE 4.7. Re je c tion r
e gion using
t: le ft- tail alte r
native hypothe sis F
IGURE 4.8. p-value using t: le ft- tail
alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
Non Rejection Region NRR Rejection Region RR
n k
t
n k
t
Non rejected for α>p-value Rejected for ɑ<p-value
n k
t
p-value
ˆ j
t
[10]
F
IGURE 4.9. E
xample 4.2: Re je c tion r e gion using t with a le ft- tail alte r native hypothe sis. F
IGURE 4.10. E
xample 4.2: p-value using t with a le ft- tail alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.2 Has income a negative influence on infant mortality?
1 2 3
5 deathun gnipc ilitrate u
(5.93) (0.00028) (0.183)
5 27.91 0.000826 2.043
i i i
deathun gnipc ilitrate =
2 1 2
: : H H
2 2
ˆ 0.000826 2.966 ˆ 0.00028 ( ) t se
[11]
F
IGURE 4.11. Re je c tion r
e gion using
t: two- tail alte r
native hypothe sis. F
IGURE 4.12. p-value using t: two-
tail alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
[12]
T
ABL E 4.2. Standar
d output in the r e gr e ssion e xplaining house pr ic e . n=55.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.3 Has the rate of crime play a role in the price of houses in an area?
1 2 3 4
price rooms lowstat crime u
(8022) (1210) (80.7) (960)
15694 6788 268.2 3854
i i i i
price rooms lowstat crime = - +
1 4
: : H H
4 4
ˆ 3854 4.016 ˆ 960 ( ) t se
Variable Coefficient
t-Statistic Prob. C
8021.989
0.0559 rooms 6788.401 1210.72 5.60691 0.0000 lowstat
80.70678
0.0017 crime
959.5618
0.0002
[13]
F
IGURE 4.13. E
xample 4.3: p-value using t with a two- tail alte r native hypothe sis.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.3 Has the rate of crime play a role in the price of houses in an area? (Continuation)
[14]
T
ABL E 4.3. Standar
d output in a r e gr e ssion e xplaining e xpe nditur e in fr
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.4 Is the e lastic ity e xpe nditur e in fr uit/ inc ome e qual to 1? Is fr uit a luxur y good?
1 2 3 4
ln( ) ln( ) fruit inc househsize punders u
(3.701) (0.512) (0.179) (0.013)
ln( ) 9.768 2.005ln( ) 1.205 0.018 5
i i i i
fruit inc househsize punder = - +
1 2 1 2
: 1 : 1 : 1 H H H
2 2 2 2 2
ˆ ˆ 1 2.005 1 1.961 ˆ ˆ 0.512 ( ) ( ) t se se
Variable Coefficient
t-Statistic Prob. C
3.701469
0.0122 ln(inc) 2.004539 0.51237 3.912286 0.0004 househsize
0.178646
0.0000 punder5
0.013022
0.1767
[15]
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.5 Is the Madr id stoc k e xc hange mar ke t e ffic ie nt?
Rate o f to tal re turn:
1 t t t t t
P D A RA P
+ +
Rate o f re turn due to inc re ase in quo tatio n Pro po rtio nal c hang e : Chang e in lo g arithms:
2 ln
t t
RA P D
1
1
t t t
P RA P
1 (0.0007) (0.0629) 2
92 0.0004 0.1267 92 0.0163 247
t t
rmad rmad R n
= =
1 2 1
92 92
t t t
rmad rmad u
E XAMPL E 4.6 Is the r ate of r e tur n of the Madr id Stoc k E xc hange affe c te d by the r ate
e tur n of the T
xc hange ?
(0.0007) (0.0375) 2
92 0.0005 0.1244 92 0.0452 235
t t
rmad rtok R n + = =
1 2
92 92
t t t
rmad rtok u
2 1 2
: 1 : 1 H H
2 2
ˆ 0.1267 2.02 ˆ 0.0629 ( ) t se
2 1 2
: 1 : 1 H H
2 2
ˆ 0.1244 3.32 ˆ 0.0375 ( ) t se
[16]
F
IGURE 4.14. Confide nc e inte r
vals for mar ginal pr
e xample 4.1.
4 Hypothesis testing in the multiple regression model
[17]
T
ABL E 4.4. Standar
d output of the e stimation of the pr
mode l (4- 20).
4 Hypothesis testing in the multiple regression model Variable Coefficient
t-Statistic Prob. constant 1.170644 0.326782 3.582339 0.0015 ln(labor) 0.602999 0.125954 4.787457 0.0001 ln(capital ) 0.37571 0.085346 4.402204 0.0002
1 2 3
ln( ) ln( ) ln( )
labor capital u
E XAMPL E 4.7 Ar e the r e c onstant r e tur ns to sc ale in the c he mic al industr y?
(0.327) (0.126) (0.085)
ln( ) 1.170 0.603ln( ) 0.376ln( )
i i i
labor capital = + +
2 3 1 2 3
: 1 : 1 H H
[18]
T
ABL E 4.5. Covar
ianc e matr ix in the pr
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.7 Ar e the r e c onstant r e tur ns to sc ale in the c he mic al industr y? (Cont.) a) Pr
e : using c ovar ianc e matr ix of e stimator s.
2 3 2 3 2 3
ˆ ˆ ˆ ˆ ˆ ˆ var( ) var( ) var( ) 2 covar( , )
2 3 2 3
ˆ ˆ ˆ ˆ ( ) var( ) se
2 3
2 3 ˆ ˆ 2 3
ˆ ˆ 1 0.02129 0.3402 ˆ ˆ 0.0626 ( ) t se
2 3
ˆ ˆ ( ) 0.015864 0.007284 2 0.009616 0.0626 se
[19]
T
ABL E 4.6. E
stimation output for the pr
e par ame te r ize d mode l.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.7 Ar e the r e c onstant r e tur ns to sc ale in the c he mic al industr y? (Cont.) b) Pr
e : r e par ame te r izing the mode l by intr
ame te r .
2 3 2 3
1 1
1 3 3
ln( ) ( 1)ln( ) ln( )
labor capital u
1 3
ln( / ) ln( ) ln( / )
labor capital labor u ˆ 0.02129 0.3402 ˆ 0.0626 ( ) t se
1 1
: : H H Variable Coefficient
t-Statistic Prob. constant 1.170.644 0.326782 3.582.339 0.0015 ln(labor)
0.062577
0.7366 ln(capital/labor) 0.375710 0.085346 4402204 0.0002
[20]
T
ABL E 4.7. Standar
d output of the r e gr e ssion for e xample 4.8.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.8 Adve r tising or inc e ntive s?
1 2 3
sales advert incent u
Variable Coefficient
t-Statistic Prob. constant 396.5945 3548.111 0.111776 0.9125 advert 18.63673 8.924339 2.088304 0.0542 incent 30.69686 3.60442 8.516448 0.0000
[21]
T
ABL E 4.8. Covar
ianc e matr ix for e xample 4.8.
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.8 Adve r tising or inc e ntive s? (Continuation)
3 2 1 3 2
: : H H
3 2
ˆ ˆ ( ) 79.644 12.992 2 2.941 9.3142 se
3 2
3 2 ˆ ˆ 3 2
ˆ ˆ 30.697 18.637 1.295 ˆ ˆ 9.3142 ( ) t se
[22]
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.9 T e sting the hypothe sis of homoge ne ity in the de mand for fish
1 2 3 4
ln( ln( ) ln( ) ln( ) fish fishpr meatpr cons u
(2.30) (0.133) (0.112) (0.137)
ln( 7.788 0.460ln( ) 0.554ln( ) 0.322ln( )
i i i i
fish fishpr meatpr cons
+
Homoge ne ity r e sstr ic tion:
2 3 4 2 3 4
1 3 4
ln( ln( ) ln( ) ln( ) fish fishpr meatpr fishpr cons fishpr u
(2.30) (0.1334) (0.112) (0.137)
ln( 7.788 0.4596ln( ) 0.554ln( ) 0.322ln( )
i i i i
fish fishpr meatpr cons
+ ˆ 0.4596 3.44 ˆ 0.1334 ( ) t se
[23]
F
IGURE 4.15. Re je c tion r
e gion and non r e je c tion r e gion using F distr ibution. F
IGURE 4.16. p-value using F
distr ibution.
4 Hypothesis testing in the multiple regression model
Non Rejection Region NRR Rejection Region RR
, q n k
F
, q n k
F
p-value F
, q n k
F
Non rejected for <p-value Rejected for p-value
[24]
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.10 Wage , e xpe r ie nc e , te nur e and age
1 2 3 4 5
ln( ) wage educ exper tenure age u
ln( ) 6.476 0.0658 0.0267 0.0094 0.0209 5.954
i i i i i
wage educ exper tenure age RSS = + +
4 5 1
: : is not true H H H
1 2 3
ln( ) wage educ exper u
ln( ) 6.157 0.0457 0.0121 6.250
i i i
wage educ exper RSS = + + =
(6.250 5.954) / 2 1.193 / ( ) 5.954 / 48
R UR UR
RSS RSS q F RSS n k
[25]
F
IGURE 4.17. E
xample 4.10: Re je c tion r e gion using F distr ibution (α value s ar e fr
4 Hypothesis testing in the multiple regression model
2.48
F
5.18 3.23 2.42 0.10 0.05 0.01 1.193 Non rejected Region NRR Rejection Region RR
E XAMPL E 4.10 Wage , e xpe r ie nc e , te nur e and age . (Continuation)
[26]
F
IGURE 4.18. E
xample 4.11: p-value using F distr ibution (α value s ar e for a F3,140)
3,205
F
3,92 2,67 2,12 26,93 0,10 0,05 0,01 0,0000 p-value
3,205
F
3,92 2,67 2,12 26,93 0,10 0,05 0,01 0,0000
3,205
F
3,92 2,67 2,12 26,93 0,10 0,05 0,01 0,0000 p-value
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.11 Salar ie s of CE Os
1 2 3 4
ln ln salary sales roe ros u
2 3 4 1
: : is not true H H H
( )
( )
2
ln 4.3117 0.2803ln 0.0174 0.00024 0.283 209
i i i i
salary sales roe ros R n = + + + = =
[27]
T
ABL E 4.9. Comple te output fr
4 Hypothesis testing in the multiple regression model
Dependent Variable: LOG(SALARY) Method: Least Squares Date: 04/12/12 Time: 19:39 Sample: 1 209 Included observations: 209 Variable Coefficient
t-Statistic Prob. C 4.311712 0.315433 13.66919 0.0000 LOG(SALES) 0.280315 0.03532 7.936426 0.0000 ROE 0.017417 0.004092 4.255977 0.0000 ROS 0.000242 0.000542 0.446022 0.6561 R-squared 0.282685 6.950386 Adjusted R-squared 0.272188 0.566374 S.E. of regression 0.483185 1.402118 Sum squared resid 47.86082 1.466086 Log likelihood
26.9293 Durbin-Watson stat 2.033496 0.0000 Mean dependent var S.D. dependent var Akaike info criterion Schwarz criterion F-statistic Prob(F-statistic)
E XAMPL E 4.11 Salar ie s of CE
[28]
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.12 An additional r e str ic tion in the pr
(Continuation of e xample 4.7)
1 2 3
ln( ) ln( ) ln( ) 0.8516
UR
labor capital u RSS
2 3 1 1
1 : : is not true H H H
3 3
ln( ) (1 )ln( ) ln( )
labor capital u
3
ln( / ) ln( / ) 3.1101
R
capital labor u RSS
(3.1101 0.8516) / 2 13.551 / ( ) 0.8516 / (27 3)
R UR UR
RSS RSS q F RSS n k
[29]
F
IGURE 4.19. Re lationship be twe e n a F1,n-k and t n-k.
4 Hypothesis testing in the multiple regression model
[30]
4 Hypothesis testing in the multiple regression model
E XAMPL E
e in the final e xam with 7 mar ks in the fir st shor t e xam?
F itte d mo de l: F itte d mo de l with the re g re sso r sho rte x1º=7: T he po int pre dic tio n fo r sho rte x1º=7: =7.593 T he lo we r and uppe r bo unds o f a 95% CI : T he po int pre dic tio n by an alte rnative way: E stimatio n o f the se o f whe re 1.649 is the “S. E . o f re g re ssio n” o btaine d fro m the E
T he lo we r and uppe r bo unds o f a 95% pro bability inte rval:
2 (0.715) (0.123)
ˆ 4.155 0.491 1 1.649 0.533 16
i i
finalmrk shortex R n s = + = = =
[ ]
2 (0.497) (0.123)
ˆ 7.593 0.491 1 7 1.649 0.533 16
i i
finalmrk shortex R n s = +
= =
ˆ
0.05/2 14 0.05/2 14
ˆ ˆ ( ) 7.593 0.497 2.14 6.5 ˆ ˆ ( ) 7.593 0.497 2.14 8.7 se t se t q q q q q q =
=
= = + ´ = + ´ =
4.155 0.491 7 7.593 finalmrk = + ´ =
1 2 2 2 2 2 2
ˆ ˆ ˆ ( ) ( ) 0.497 1.649 1.722 se e se y
2
ˆ e
0.025 2 14 0.025 2 14
ˆ ˆ ( ) 7.593 1.722 2.14 3.7 ˆ ˆ ( ) 7.593 1.722 2.14 11.3 y y se e t y y se e t
[31]
T
ABL E 4.10. De sc r
iptive me asur e s of var iable s of the mode l on CE Os salar y.
4 Hypothesis testing in the multiple regression model
T
ABL E 4.11. Pr
e dic tions for se le c te d value s.
E XAMPL E 4.14 Pr e dic ting the salar y of CE Os
(104) (0.0013) (8.671) (0.0538) 2
1381 0.008377 32.508 0.2352 ˆ 1506 0.2404 447
i i i i
salary assets tenure profits R n s = + + + = = = assets tenure profits Mean 27054 7.8 700 Median 7811 5.0 333 Maximum 668641 60.0 22071 Minimum 718 0.0
Observations 447 447 447
Prediction
Mean values 2026 71 Median value 1688 78 Maximum values 14124 1110 Minimum values 760 195 ˆ ˆ
[32]
4 Hypothesis testing in the multiple regression model
E XAMPL E 4.15 Pr e dic ting the salar y of CE Os with a log mode l (c ontinuation 4.14)
(0.210) (0.0232) (0.0032) (0.0000195) 2
ln( ) 5.5168 0.1885ln( ) 0.0125 0.00007 ˆ 0.5499 0.2608 447
i i i i
salary assets tenure profits R n s = + + + = = =
Inc onsiste nt pr e dic tion Consiste nt pr e dic tion
exp(ln( )) exp(5.5168 0.1885ln(10000) 0.0125 10 0.00007 1000) 1207
i i
salary salary = = + + ´ + ´ =
2
exp(0.5499 / 2) 1207 1404 salary = ´ =