In: Statistics and Probability
A large firm employing tens of thousands of workers has been accused of discriminating against its female managers. The accusation is based on a random sample of 40 managers. The mean annual salary of the 20 female managers is $79,500 while the mean annual salary of the 20 male managers is $103,250. The president of the firm points out that the company has a strict policy of equal pay for equal work and that the difference may be due to other variables. Accordingly, he found and recorded the number of years of education and the number of years of experience for each of the 40 managers in the sample. Also recorded are the salary and gender (1 = female and 0 = male). The data are in attached Excel document. The president wanted to know whether a regression analysis would shed some light on the issue.
Use Microsoft Excel to run a regression of annual salary on years of education, years of experience, and gender and round up numbers in your regression results to 2 decimal points. Please use the level of significance of 10 percent (i.e. α = 0.10). On the basis of your Excel results answer following questions.
. Clearly interpret the numerical values of estimated coefficients of our explanatory
variables which are years of education, years of experience and gender.
Annual Salary(in $1000.00) |
Education(in years) |
Experience(in years) |
Gender |
130 |
20 |
18 |
0 |
80 |
19 |
16 |
1 |
62 |
18 |
8 |
1 |
176 |
18 |
30 |
0 |
44 |
14 |
9 |
1 |
139 |
16 |
22 |
0 |
165 |
18 |
27 |
0 |
112 |
19 |
20 |
1 |
92 |
16 |
17 |
1 |
84 |
18 |
13 |
1 |
106 |
14 |
17 |
0 |
103 |
22 |
24 |
1 |
98 |
16 |
18 |
0 |
93 |
17 |
14 |
1 |
79 |
16 |
14 |
1 |
92 |
16 |
14 |
0 |
79 |
14 |
16 |
0 |
98 |
20 |
18 |
1 |
111 |
19 |
25 |
1 |
45 |
15 |
10 |
0 |
82 |
16 |
13 |
0 |
100 |
19 |
21 |
1 |
88 |
15 |
15 |
0 |
76 |
18 |
13 |
1 |
123 |
16 |
21 |
0 |
120 |
17 |
22 |
0 |
50 |
18 |
7 |
1 |
30 |
17 |
4 |
1 |
135 |
16 |
19 |
0 |
84 |
14 |
17 |
0 |
50 |
16 |
6 |
1 |
65 |
15 |
9 |
0 |
83 |
17 |
12 |
1 |
105 |
21 |
21 |
1 |
70 |
17 |
10 |
1 |
99 |
15 |
12 |
0 |
89 |
18 |
8 |
0 |
93 |
15 |
14 |
0 |
68 |
17 |
11 |
1 |
57 |
15 |
10 |
0 |
SUMMARY OUTPUT | ||||||||
Regression Statistics | ||||||||
Multiple R | 0.92 | |||||||
R Square | 0.84 | |||||||
Adjusted R Square | 0.83 | |||||||
Standard Error | 12.80 | |||||||
Observations | 40 | |||||||
ANOVA | ||||||||
df | SS | MS | F | Significance F | ||||
Regression | 3 | 32022.63 | 10674.21 | 65.14 | 0.00 | |||
Residual | 36 | 5898.74 | 163.85 | |||||
Total | 39 | 37921.38 | ||||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | Lower 95.0% | Upper 95.0% | |
Intercept | -2.90 | 20.29 | -0.14 | 0.89 | -44.05 | 38.25 | -44.05 | 38.25 |
Education(in years) | 2.49 | 1.45 | 1.72 | 0.09 | -0.45 | 5.42 | -0.45 | 5.42 |
Experience(in years) | 4.01 | 0.42 | 9.51 | 0.00 | 3.15 | 4.86 | 3.15 | 4.86 |
Gender | -18.78 | 5.35 | -3.51 | 0.00 | -29.64 | -7.92 | -29.64 | -7.92 |
Years of education: Significant at 90% since p value is less than 0.1
For every additional year in education there is an average increase of $2490 salary provided all other factors are the same
Experience : Significant at 90% since p value is less than 0.1
For every additional year of experience, there is an average increase of $4010 of salary provided all other factors are the same
Gender: Significant at 90% since p value is less than 0.1
Females on an average earn 1878 dollars less than males provided all other factors remain the same