Gender pay gaps in academia have been documented for decades, but why they persist remains an open question. A new study published in the Proceedings of the National Academy of Sciences (PNAS) examined several leading explanations, including whether differences in research productivity, salary transparency and female representation among faculty account for the disparity. Researchers from the University of California San Diego’s School of Global Policy and Strategy and Rady School of Management analysed faculty salaries across all 10 University of California campuses in anthropology, business, economics, political science, sociology and several smaller social science disciplines. Overall, women earned 23% less than men. After accounting for field, campus and career start date, the gap narrowed to 4.3%, suggesting that other factors contribute to the remaining difference.

One common explanation is that men earn more because they produce more research. To test this, the researchers matched University of California salary records with publication and citation data from Scopus author profiles, while also accounting for academic rank. Faculty with more publications and citations generally earned higher salaries, confirming that research output influences pay. However, including these measures had little effect on the remaining 4.3% gender pay gap. “We tested one of the most common explanations for gender pay gaps in academia: that differences in pay reflect differences in measurable productivity,” said corresponding author Elizabeth Lyons, associate professor at the UC San Diego School of Global Policy and Strategy. “What we found is that productivity matters for pay, but it does not explain away the gender gap.”

The researchers also explored whether salary transparency helps reduce pay inequities. Because faculty salaries in the University of California system are publicly available, the university provided a natural setting to examine this idea. Despite this transparency, gender pay disparities remained. The findings do not suggest that making salaries public lacks value, the authors note, but they indicate that transparency by itself is unlikely to eliminate pay inequities without additional institutional changes.

The study also revealed that gender pay gaps differed substantially across academic disciplines. After accounting for observable factors, significant pay gaps remained in business, sociology and anthropology. In contrast, no statistically detectable gap was found in economics, political science or the smaller social science fields grouped as “other.” One of the most striking comparisons involved economics and anthropology. Women represented fewer than one in five economics faculty members during the study period, yet no measurable pay gap was detected. By contrast, anthropology had roughly equal numbers of male and female faculty, but women still earned about 93 cents for every dollar earned by men. “Women’s representation in the faculty matters and deserves to be better understood, but it won’t necessarily fix the pay gap,” said co-author Gaurav Khanna. “Representation does not necessarily predict pay equality.”

The variation among disciplines suggests that structural differences may influence compensation. Economics and political science often have more centralised academic labour markets and clearer standards for evaluating research. At the same time, anthropology and sociology place greater emphasis on books and monographs, making scholarly output more difficult to compare consistently. Business disciplines may also be affected by differences among specialisations, with men more heavily represented in higher-paying areas such as finance. These differences may help explain why pay gaps are more pronounced in some fields than others.

Although the study does not identify a single solution, it suggests that universities could learn from disciplines where pay disparities are smaller. “The variation across fields matters because it shows these gaps are not inevitable,” said co-author Marta Serra-Garcia, professor at the Rady School of Management. “It also gives universities a place to start—by asking what fields with smaller gaps may be doing differently.” The findings suggest that closing gender pay gaps will likely require more than improving productivity measures, increasing transparency or expanding female representation alone. Instead, institutions may need to examine how discipline-specific hiring, evaluation and compensation practices shape salary outcomes.

More information: Ayelet Gneezy et al, Gender pay gaps in the social sciences, Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2524119123

Journal information: Proceedings of the National Academy of Sciences Provided by University of California – San Diego