A study released las month by the University Center for Social and Urban Research at the University of Pittsburgh on the the economic and educational status of women in Pittsburgh was not good news: Although women in the region are increasingly well-educated, and their labor force participation has been going up, their salaries still lag far behind women working in other American cities. Women in this region have invested heavily in higher education, but this investment has not had the same payoff in higher wages that men in Pittsburgh, or women in other regions, have experienced.

Two recent studies that we directed, a survey of college graduates from Pittsburgh universities and a survey of executive directors of Pittsburgh area non-profits, confirm these census results and suggest one reason for these disparities: More women than men are employed by non-profits, which tend to pay lower salaries than do for-profit employers. And Pittsburgh has a higher proportion of non-profits (including educational institutions and medical facilities as well as arts and social-service organizations) than do other American cities.

But the problem may not only be the concentration of non-profits here. We also found that Pittsburgh-area non-profits pay women far less than they do men. Even if we take into account years of employment, advanced degrees or field of study, women working for non-profits still report earning less than males with comparable positions. Even worse, the gender differences in pay for Pittsburgh-area non-profits are in fact worse than gender disparities in the for-profit sector! And the sex differences in both non-profit and for-profit salaries are much wider in Pittsburgh than in other cities.

This gender gap is clear for those just beginning their careers. It is also true for those at the very top of non-profit organizations. When we look at executive directors, the larger the organization, the less likely it is to be headed by a woman, and women executive directors are paid less than men who head comparably sized organizations.

So why are women working for non-profits paid so little? There is a large body of research on the gender gap. Among the possible reasons why women receive lower salaries are differences in education and experience and occupational segregation. Jobs traditionally considered "women's work" are often paid less. But these explanations don't clearly apply here. The census data reported higher levels of education for women, and we found that women with graduate degrees were more likely to work in nonprofits. And we have no evidence that women are channeled into different career tracks within the non-profit community.

Another explanation is plain old discrimination. We doubt that many non-profits discriminate consciously, but most non-profits are small, and human resources issues such as hiring and setting salaries are often handled informally.

Without accurate data on salaries, some non-profits may not be able to see the big picture, which would show them that they are contributing to this problem by paying women less than men would receive for similar work.

A recent study ("Women Don't Ask: Negotiation and the Gender Divide" by Linda Babcock and Sara Laschever) provides another explanation: Women are less effective at negotiating salaries, both when they first enter the labor market and as they move up. That may be particularly true for women in the non-profit sector, since the college grads we surveyed who are working for non-profits placed a higher emphasis on finding jobs "doing good or helping others" than did graduates now employed by for-profits.

Women in our sample were also more likely than men to say that they took jobs in order to "gain experience," and were perhaps more willing to tolerate lower pay in exchange.

Non-profits rely on these norms in order to attract well-trained young professionals. And of course many non-profits have faced rising caseloads, increased operating costs, and recent stock-market fluctuations. Still, non-profit employers need to look closely at whether they are living up to their own values.

If they are interested in retaining as well as attracting well-educated young professionals, in moving younger employees into leadership positions within their organizations, and in treating all their employees fairly, they cannot afford to denigrate the talents of their predominantly female labor force.

Instead of lagging behind the for-profit sector with respect to gender equity, non-profits should be pointing the way to a better future in which women in the Pittsburgh region receive just compensation for their investment in education and their experience.