Economics 120B
Name:
_________________________
Professor Yongil Jeon
June 8, 2005
Student ID#: _________________________
Answers to Exam 3:
Econometrics
B
Econ 120b, Spring 2005
1.
(10 points)
Based on a sample of sixtyfour observations, the following model was
estimated by least squares:
y
= 16.528 + 28.729 x
1
+0.022 x
2
0.023 x
3
0.054 x
4
0.077 x
5
+0.411 x
6
+0.349 x
7
+0.028 x
8
, R
2
=0.476
where
y
=
index of direct labor efficiency in production plant
x
1
=
ratio of overtime hours to straighttime hours worked by all production workers
x
2
= average number of hourly workers in the plant
x
3
= percentage of employees involved in some qualityofworklife program
x
4
= number of grievances filed per 100 workers
x
5
= disciplinary action rate
x
6
= absenteeism rate for hourly workers
x
7
= salaried workers’ attitudes, from low (dissatisfied) to high, as measured by
questionnaire
x
8
= percentage of hourly employees submitting at least one suggestion in a year to the
plant’s suggestion program
Also obtained by least squares from these data was the fitted model:
y
= 9.062 10.944 x
1
0.320 x
2
+0.019 x
3
, R
2
=0.325
The variables x
4,
x
5,
x
6,
x
7,
x
8
are measures of the performance of a plant’s industrial
relations system. Test at the 1% level the null hypothesis that they contribute nothing to
explaining direct labor efficiency, given that x
1
,x
2
, x
3
are also to be used.
Note that
(9,64,0.01)
2.70
F
=
,
(9,55,0.01)
2.75
F
=
,
(4,64,0.01)
3.63
F
=
,
(4,55,0.01)
3.68
F
=
.
Answer
).
8
,
7
,
6
,
5
,
4
(
0
:
0
:
1
8
7
6
5
4
0
=
≠
=
=
=
=
=
i
one
least
At
H
vs
H
i
β
Then,
()
804
.
5
)
1
8
64
/(
0.467
1
4
/
0.242

0.467
)
1
/(
1
/
2
2
2
=
−
−
−
=
−
−
−
−
=
k
n
R
q
R
R
F
UR
UR
r