COLLEGES and universities in the United States are hiring more and more full-time non-tenure-track professors and paying them less than senior faculty to work longer hours - with no job security, sabbaticals or other perks.
Far more women than men are being hired to fill these jobs, according to a national study by researchers at the University of Virginia and the College of William and Mary.
While all non-tenure-track positions generally pay less than tenure-track, women still earn less than men of the same rank, by an average of 20 per cent.
Ernst Benjamin, director of research for the American Association of University Professors, said: "These faculty are paid less because they don't have an alternative. The market is generally down and there are changes in the kind of jobs they're being offered.
"Clearly it's a market-driven phenomenon. Universities and colleges may claim to be doing it for flexibility but I think they're doing it to save salary."
Salaries averaged about $41,100 (Pounds 25,200) for non-tenure-track males and $33,200 for women, compared with the national average of $78,200 for a tenured full professor.
Several factors contribute to the gender disparity. Men in non-tenure-track positions produced more than twice as many scholarly works, including books, than women. Female non-tenure-track faculty are more likely to be employed in lower-paying traditionally female fields, such as education and health science. And about 33 per cent of full-time male non-tenure-track faculty hold doctorates, compared with slightly more than 21 per cent of full-time non-tenure-track female faculty.
Non-tenure-track instructors are ineligible for the job security enjoyed by senior faculty, even though they work full-time. They also generally put in more hours for less pay and cannot apply for research grants.
The number of women in these positions has increased 142 per cent in the past 18 years. The number of non-tenure-track men rose 54 per cent during the same period.
Sandra Eaglen is a non-tenure-track English professor at Kent State University, where one non-tenure-track position in her department recently drew 300 applicants. She said: "It's gotten that there are so many people out there begging for jobs, particularly in the liberal arts, that it's a buyer's market." Many non-tenure-track professors are being hired to work in proliferating branch campuses being opened in response to a demand from working students for classes near their homes.
"There's this idea that people at the regional campuses don't need to be as published or as professionally known," Ms Eaglen said. "And it's exceedingly cheaper to hire non-tenure-track professors."
The same thinking has spurred a simultaneous sharp rise in the number of part-time instructors.
Dr Benjamin said both trends reduce the quality of higher education. Full-time, non-tenure-track faculty tend to teach basic and remedial courses that their more senior counterparts disdain. "That raises issues about their ability to introduce students to the major and to advise students," he said. "They're likely not to be there as long. And they're likely not to do a lot of research, so they aren't always as much at the cutting edge of their field as tenured faculty would be."