MnSCU – System Report
2002 Salary Equity Analysis
March, 2003
Prepared by:
Thomas McMullen
Senior Consultant
Hay Group
Eric Jacobs
Consultant
Hay Group
Malcolm M. Dow
Professor Emeritus
Northwestern University
Table of Contents
I. Executive Summary.................................................................................................... 1
II. Faculty Salary Equity Analysis................................................................................... 2
A. Controlling Salary For Structural Factors: Multiple Regression Analysis................. 2
B. Individual-level Salary Differences: Regression Residuals..................................... 11
C. Summary................................................................................................................... 11
This statistical analysis of the System faculty salary data used the Multiple Regression model to predict salaries based on a number of factors known to affect pay. Variables coding for campus location were included in the analyses. No faculty performance measures were included.
A set of location dummy (0,1) variables were included in one of the regression analysis to assess overall differences across campuses. This regression analysis revealed a spread of approximately 5.5% (-3.3% to +2.2%) in average salaries across campuses, after controlling for all of the other variables in the model.
The regression analysis using years in current rank and other time-related variables, plus the squares of these variables, showed no evidence of salary compression for faculty with many years in rank. However, the appointment status variables suggest that hiring faculty at the higher academic ranks but without tenure, and at higher average annual salaries than comparable tenured faculty, may lead to salary compression problems in the future.
At the individual level, shortfalls between actual salary and salary predicted by the Total Population regression model (without location), as indicated by standardized residuals of less than -1.00, were noted for 278 faculty across all campuses.
1. Total Population Salary Analysis – with and without location
Table 1 reports the estimated regression equation and auxiliary statistics for the Total Population Analysis (N=2,370). In this model, the dependent variable is 2002 Annual Salary, and the predictor variables are all of the structural variables.
The first column of Table 1 shows the labels of each of the variables entered into the regression model. The first term (constant) can be ignored. Each of the other terms in the first column corresponds to a “structural” variable. The second column in Table 5 shows the “unstandardized coefficient” B associated with each variable, which indicates the average amount by which each faculty member’s salary increases (or decreases) for a one unit change in the corresponding variable, all of the other variables in the equation being held constant. In the case of a dummy variable, the one unit change is from the omitted reference category (coded as 0) to the corresponding category (coded as 1). So, for example, the coefficient for Associate Professor in the second column indicates that an individual moving from the “Professor” category (coded as 0) to the “Associate Professor” category (coded as 1) would be expected to have a decrease in annual salary of $3,490, all other variables in the regression model being held constant. That is, this figure is simply the difference in average salaries between the two ranks controlling for all other variables in the model. For continuous variables, such as Years since Highest Degree, the corresponding unstandardized coefficient ($87) indicates how much each additional unit (here, a year) is worth, on average.
Table 1. Total Population Model with Discipline, no Location.
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|
|
Unstandardized |
Standardized |
t |
Sig. |
Collinearity |
||
|
B |
Std. Error |
Beta |
Tolerance |
VIF |
|||
|
(Constant) |
57060 |
428 |
|
133.403 |
0.000 |
|
|
|
|
|
|
|
|
|
|
|
|
ACCTG |
11110 |
716 |
0.129 |
15.520 |
0.000 |
0.743 |
1.346 |
|
ALHEL |
1477 |
894 |
0.013 |
1.652 |
0.099 |
0.846 |
1.182 |
|
ARTFI |
795 |
758 |
0.010 |
1.049 |
0.294 |
0.595 |
1.679 |
|
AVIAT |
2928 |
1448 |
0.015 |
2.022 |
0.043 |
0.927 |
1.079 |
|
BIOLO |
1007 |
574 |
0.016 |
1.756 |
0.079 |
0.645 |
1.549 |
|
BUSLW |
7339 |
1445 |
0.039 |
5.080 |
0.000 |
0.847 |
1.180 |
|
CHEMS |
-15 |
719 |
0.000 |
-0.021 |
0.983 |
0.765 |
1.308 |
|
CISCS |
10744 |
557 |
0.175 |
19.284 |
0.000 |
0.622 |
1.609 |
|
COUED |
1477 |
918 |
0.012 |
1.609 |
0.108 |
0.861 |
1.161 |
|
COUNS |
594 |
854 |
0.005 |
0.696 |
0.487 |
0.841 |
1.189 |
|
CRMJS |
1790 |
985 |
0.014 |
1.817 |
0.069 |
0.876 |
1.141 |
|
CULTR |
1758 |
722 |
0.020 |
2.435 |
0.015 |
0.775 |
1.291 |
|
ECONO |
5325 |
735 |
0.059 |
7.245 |
0.000 |
0.778 |
1.285 |
|
EDBUS |
4146 |
2003 |
0.015 |
2.070 |
0.039 |
0.967 |
1.034 |
|
EDCAD |
2753 |
937 |
0.023 |
2.937 |
0.003 |
0.857 |
1.167 |
|
EDCGN |
1223 |
499 |
0.024 |
2.448 |
0.014 |
0.517 |
1.933 |
|
EDCSP |
1324 |
844 |
0.012 |
1.568 |
0.117 |
0.835 |
1.198 |
|
ENGIN |
11895 |
849 |
0.110 |
14.009 |
0.000 |
0.825 |
1.212 |
|
(ENGLISH) |
|
|
|
|
|
|
|
|
FINAN |
13746 |
880 |
0.121 |
15.626 |
0.000 |
0.845 |
1.184 |
|
GEOGR |
453 |
774 |
0.005 |
0.586 |
0.558 |
0.802 |
1.246 |
|
HISTY |
-713 |
729 |
-0.008 |
-0.978 |
0.328 |
0.775 |
1.290 |
|
HOMEC |
-725 |
2007 |
-0.003 |
-0.361 |
0.718 |
0.963 |
1.038 |
|
LANGS |
-744 |
745 |
-0.008 |
-1.000 |
0.318 |
0.791 |
1.264 |
|
LIBRY |
1104 |
611 |
0.017 |
1.809 |
0.071 |
0.606 |
1.649 |
|
MARKT |
13055 |
819 |
0.126 |
15.931 |
0.000 |
0.813 |
1.229 |
|
MATHM |
1553 |
520 |
0.028 |
2.985 |
0.003 |
0.578 |
1.730 |
|
MEDIA |
1345 |
757 |
0.014 |
1.776 |
0.076 |
0.782 |
1.279 |
|
MNGMT |
11974 |
665 |
0.150 |
17.994 |
0.000 |
0.736 |
1.359 |
|
MUSIC |
-542 |
616 |
-0.008 |
-0.880 |
0.379 |
0.702 |
1.424 |
|
NURSE |
3579 |
613 |
0.053 |
5.839 |
0.000 |
0.615 |
1.626 |
|
PHILO |
281 |
799 |
0.003 |
0.351 |
0.725 |
0.812 |
1.232 |
|
PHYED |
532 |
543 |
0.011 |
0.979 |
0.328 |
0.397 |
2.522 |
|
PHYSC |
1598 |
688 |
0.019 |
2.322 |
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