Determinants of Political Science Faculty Salaries at the University of California

Combining salary data for permanent non-emeritus faculty at seven departments of political science within the University of California system with lifetime citation counts and other individual-level data from the Masuoka, Grofman, and Feld (2007a) study of faculty at Ph.D.-granting political science departments in the United States, I analyze determinants of faculty salaries. For the full data set the main finding are that (1) base salaries of UC political science faculty are slightly more strongly correlated to citation rates (annualized or total lifetime citations) as ameasure of research visibility than they are to seniority measured by years since receipt of the Ph.D.; and (2) that gender differences and subfield differences in salary essentially vanish once I take into account both year of Ph.D. and research visibility (as measured by annualized citation counts), while gender inequities would appear to exist if I did not control for both variables. INTRODUCTION Questions about the determinants of faculty salary are of general interest. Of particular concern are issues of the relationship between seniority and compensation, gender and compensation, and research performance and compensation. Here I take advantage of data involving seven departments of political sciencewithin theUniversity of California (UC) systemwhere Iwas able to combine publicly available salary information with lifetime citation counts and other individual-level data from the Masuoka, Grofman, and Feld (2007a) study of faculty at Ph.D.-granting political science departments in theUnited States.1 While this study is limited to the determinants of faculty salaries in political science departments within the UC system, I believe that the results have broader implications. Theory How might we predict the relative weight of different factors in the determination of base salaries? There are competing theoretical expectations as towhatwe shouldfind.Thebureaucraticmodel suggests that, because performance is at least in part a contested concept within academia,2 and because the UC system is a large bureaucracy, the systemmay cope with salary determination with fixed rules that establish a time-based ladder of salary increments that is uniformly applied across all campuses. Indeed, such rules exist in the Academic Personnel system of the university. To the extent that we have bureaucratic rigidity, we would expect a very strong correlation between salary and years since Ph.D. At the same time, the UC system and the State of California greatly value the quality and strong national reputations of the faculty and their research programs.Thus, to the extent that there is flexibility in salary determination for base salaries, and concern about recruiting and keeping first-rate faculty, I expect the administration at the various campuses to respond to both equity and market considerations by taking performance factors into account, not merely seniority. This should show up in the data as a relatively high degree of variance in the pay levels of those with similar dates of Ph.D. Another theoretical concern is how to best predict the nature of the differences in salary determination across the various UC campuses.3 One possibility is that the existence of system-wide norms and a system-wide salary ladder common to all campuses will yield very high congruence across campuses in the factors affecting salaries.4 A second possibility is that those departments with higher national visibility will, controlling for other variables, pay less because they compensate their faculty in nonmonetary ways, for example, by providing them the prestige associated with faculty status at a top department, top graduate students, or other, intellectual benefits. A third possibility is that, after controlling for other variables, top departments pay more than the less visible departments.Thismay occur if the top departments are more willing to compete aggressively for the most professionally visible and productive faculty by paying competitive salaries and beingmorewilling to tolerate salary differences across individuals with similar date of Ph.D. A fourth and related possibility is based on the idea that top departments would, in general, Bernard Grofman is professor of political science at the University of California, Irvine. In 2008 he became the inaugural JackW. Peltason (Bren Foundation) Endowed Chair, and also director ofUCI’s Center for the Study ofDemocracy.He is co-author of four books, all published by Cambridge University Press, and editor or co-editor of 17 other books; he has published over 200 research articles and book chapters; and his work has been cited inadozendifferentU.S.SupremeCourt opinions. In2001hebecameaFellowof theAmerican Academy of Arts and Sciences. The Pro fess i on ............................................................................................................................................................................................................................................................. doi:10.1017/S1049096509990175 PS • October 2009 719 pay more attention to productivity measures (relative to seniority) than would less highly ranked departments when it came to determining faculty compensation. This differentiation can also lead to variance differences across departments in the dispersion of faculty salaries for a given number of years past Ph.D.5 My analyses test the differing expectations of the bureaucratic and the performance-based models of salary determination, and of the various hypotheses about cross-campus differences in salaries and in salary determinationmethods, by using citation counts as themeasure of research performance.6While the data base does not have teaching or service information, I was able to take into account some variables not directly related to research performance that might affect salary levels: cross-campus differences, subfield differences, and gender differences. I focus on six specific questions about faculty salaries. First, how well can we predict the salaries of UC political science faculty by simply knowing the date of Ph.D.? Second, howwell does actual faculty compensation accordwith compensation determined by projecting salaries based on normal progress on the UC salary ladder for someone with a given number of years since Ph.D.? Third, what is the contribution of research performance, as measured by citation counts, to the determination of faculty salaries? Fourth, is there any evidence of a gender gap? In particular, how is any gender gap in salaries affected when I control for number of citations and other variables? Fifth, is there evidence of salary differences across political science subfields? Finally, how similar are the (inferred) salarydetermination processes at the different UC campuses? That is, are there significant intercampus differences in salaries even after controlling for the seniority and research visibility of the campus’s faculty? And, if so what is the nature of these differences? Data This project builds on a prior study of citation counts of all faculty at Ph.D.-granting political science departments in theUnited States done by Masuoka, Grofman, and Feld (2007a). Using the list of Ph.D.-granting political science department faculty as of 2002 as a basis, Masuoka, Grofman, and Feld compiled the total citation counts for each facultymember using theWeb of Science/ ISI online database.The principal investigators also coded a number of other variables I used in these analyses: the year of receipt for the Ph.D., the institution of each faculty member, field of specialization within political science, and gender. I primarily utilized career citations here, spanning the 1960–2005 period. I also calculated a measure of average citations per year since receipt of the Ph.D. Salary data are from “University of California, Fiscal Year 2005–06 Payroll Data” reports as available at the Langston Library at UC Irvine.7 I used base salary as listed in these reports, with some modification.8 My comparisons of citations are slightly more precise than those inMasuoka, Grofman, and Feld (2007a) because I restricted myself to active tenure-track faculty, which excludes emeriti and non-tenure-track appointments that are sometimes included in studies that do departmental citation counts. I also excluded UC facultymembers who held a full-time administrative position and whose salary is based on this position, such as a vice chancellor or dean. I excluded faculty who are paid on the UC salary scale for law schools in order to study faculty whose work is primarily in political science and who are evaluated within political science departments.9 This yields a total database of 153 faculty whowere employed in seven UC political science departments in 2002 and are still employed full time in 2005 (UCSantaCruz andUCMerced are not included because their Ph.D. programswere not yet established at the time the data were collected). In short, I compared how faculty salaries vary among a group who work in the same discipline of political science, and who are evaluated by a common standard of academic performance by UC political science departments and the UC Academic Personnel system. SENIORITY ANDUC BASE SALARY How strongly is seniority related to salary? I first looked at the bivariate relationships between base salary and years since Ph.D. I expected that faculty salaries generally rise with experience as people become more expert in their profession as teachers and stronger contributors to the university and the community, inways separate from research impact. I used years since receipt of the Ph.D. as a predictor of accumulated experience in the profession There is a strong positive and statistically significant relationship between years since Ph.D. and the facultymember’s 2005–06 base salary (Pearson r= .52). However, there is clear evidence of heteroscedasticity (see Figure 1). My second question is the degree of fit between base salary and the salary predicted by the UC salary ladder based on normal time in step and normal time in grade (using the 2005–06 salary schedule and accompanying documentation). I used time since Ph.D. to predict the step (and thus salary) facultymembers if they had merit evaluations on the normal time basis and had positive evaluations at each merit evaluation (using the 2005–06 salary schedule and accompanying documentation).10 The correlation between base salary and expected normal salary is .51, virtually the same as the correlation between base salary and years since Ph.D. Figure 2 groups time since Ph.D. into six-year intervals to show the average patterns in the data. Average salaries are considerably higher than the salary-scale norm for political science faculty early in their careers. For instance, there is roughly $25,000 per year in additional salary compared for those from one to 18 years past Ph.D., and an average of nearly $50,000 higher for Figure 1 Base Salary (2005–06) byYears since Ph.D. Source: Salary data from“University of California, Fiscal Year 2005–06 Payroll Data”; years since receipt of Ph.D. from Grofman, Masuoka, and Feld database. N =153. The Pro fess i on : De t e rm inan t s o f Po l i t i c a l S c i e n c e Fa cu l t y S a l a r i e s a t t h e Un i v e r s i t y o f Ca l i f o r n i a ............................................................................................................................................................................................................................................................. 720 PS • October 2009 faculty who are in their 10 to 24 year since Ph.D. (i.e., the cohort that is now about 20 years past Ph.D. seems to be especially well paid relative to Academic Personnel norms). However, the gap between theUC-ladder norm and actual salary then narrows considerably until, for most senior faculty, there is essentially no difference between what the ladder system would expect them to be paid based on normal progress and their actual baseline salaries.11 THE BASICTWO-VARIABLEMODEL: TIME SINCE PH.D. AND CITATIONS I begin this part of the analyses with a simple two-variable model to explain the base salary of UC political science faculty.12 The first variable is years since Ph.D., which we I have seen is already quite powerful in explaining salary variation.The second variable is a measure of research impact. I recognize that the research contributions of faculty can take many forms, and the recognition of these contributions can take many forms. To measure research impact I relied on citation counts for the 1960–2005 period as reported by the Web of Science/ISI database. This measure of research productivity seems preferable to other indicators, such as number of publications or external grant funding, because citations measure how much the larger scholarly community utilizes a faculty member’s research.13 Fitting my expectations, there is a strong positive relationship between the total citations and the 2005–06 base salary (r = .59). There is also an equally strong relationship between the yearly rate of a scholar’s citations (citations/ year) and base salary (r = .58). As I expected, years since Ph.D. and citation counts are positively related (r = .45), but they reflect distinctly different sources of advancement.Thus, the next step in the analysis combines both predictors in an ordinary least squares (OLS) regression to predict salary.The results are largely consistent with the above analyses for each variable separately (see Table 1). For instance, the left columns in Table 1 measure lifetime citations; a year of experience adds about $1,040 to the base salary, holding constant research citations. Each individual citation adds $36.50 on average, holding constant years since Ph.D. Similarly, the right-most columns in Table 1 use a faculty member’s annualized citation count. An increase in the average of one citation per year predicts a salary increase of $1,234, almost as much as the estimate for a year of additional seniority. The standard errors indicate that all the relationships are well above the usual levels required for statistical significance. Also, the standardized coefficients in Table 1 show that years since Ph.D. and citation counts are both important as salary determinants, but with the latter somewhat more important. To help readers understand the practical implications of these findings,Table 2 presents somedescriptive information about total citation counts and annualized citation counts for UC faculty at different stages of their careers. The average number of citations received annually by faculty is relatively low—averaging 14 per year for all faculty in the database. Moreover, as noted earlier, the average is not highly correlated with years since Ph.D.14 GENDER EQUITY The University of California is strongly committed to an equitable merit and promotion system in which faculty are evaluated on the basis of merit. There is a continuing UC concern about Figure 2 Salaries and Normal-Progress Predicted Salaries byYears since PhD Source: Salary data from“University of California, Fiscal Year 2005–06 Payroll Data”; years since receipt of Ph.D. from Grofman, Masuoka, and Feld database. N =153. Salary-ladder data for tenure-track faculty as reported by the UC Academic Personnel system for 2005–06. Table 1 Predicting UC Political Scientists Base Salary fromYears since Ph.D. and Citations (Lifetime Citations and Citations per Year) PREDICTOR UN-STANDARDIZED COEFFICIENTS STANDARDIZED COEFFICIENTS PREDICTOR UN-STANDARDIZED COEFFICIENTS STANDARDIZED COEFFICIENTS Years since Ph.D. 1,040 .32 Years since Ph.D. 1,445 .45