The fastest growing category of post-postdoc academic scientists is not the tenure-track assistant professorship to which countless postdocs aspire. It is the array of non-tenure-track jobs that carry such assorted titles as staff scientist, research associate, lecturer, and research assistant professor. Holders of these positions have "graduated" from working as trainees under a mentor's supervision but usually still have not attained a status that allows them to do independent research.

Need to clarify roles and career possibilities

The growth in this category is particularly marked in the life sciences, but is apparent in other fields as well. While the ranks of science Ph.D.s holding faculty-level jobs outside the established career ladder have multiplied in recent years, the number of traditional assistant professorships offering a shot at tenure has stagnated or even declined. Also rising is concern about this expanding cadre's duties, prerogatives, and long-term career prospects. Clarifying the roles and possibilities open to non-tenure-track university scientists and finding ways to make the best use of their talents and training presents a challenge to the leadership of the nation's research enterprise.

A committee of the National Academies' Board on Life Sciences began to tackle this issue, along with others related to the increasingly difficult career passage facing young scientists, at a day-long workshop held on 16 June at the academies' Keck Center in Washington, D.C. Entitled "Bridges to Independence: Fostering Independence of New Investigators in the Life Sciences," the gathering drew approximately 100 representatives of universities, private funding organizations, NIH institutes, and other government agencies. Plenary sessions and breakout discussions explored many aspects of the situation of young scientists in both tenure-track and non-tenure-track university jobs.

A few of these non-tenure-track positions are the "moral equivalent" of the traditional assistant professorship in that they permit or even encourage independent research--albeit on soft money, stated Keith Yamamoto, a professor of cellular and molecular pharmacology at the University of California, San Francisco. But many nontenured staff scientists "have been treated as second-class citizens in many ways," and their situation "has to be dealt with," said David Hirsch, Columbia University's executive vice president for research.

Key to the problematic status of most non-tenure-track scientists is universities' widespread refusal to allow them to apply for their own research funding, the sine qua non of scientific credibility. NIH permits grant applications from scientists without tenure-track positions, but it also requires that their proposals have institutional backing. Universities are generally loath to commit themselves to providing to individuals outside the tenure track the lab space and other resources needed for research. As the life sciences increasingly move toward interdisciplinary team projects and away from the traditional single-PI model, noted NIH Director Elias Zerhouni, the nation's funding agencies will need to "redefine career paths," possibly in ways that "empower ... very senior staff scientists."

Between 1993 and 2001, the number of life scientists under the age of 35 holding Ph.D.s from U.S. universities increased from 11,000 to about 16,000, but the number of tenure-track assistant professorships at major research universities remained steady at about 1200, said Paula Stephan, a professor of economics at Georgia State University in Atlanta. In 1993, 26% of the faculty-level positions at those institutions were outside the tenure track, as opposed to 33% in 2003, she added.

In recent years, universities increasingly have replaced tenure-track positions that fall vacant with non-tenure-track slots. At research universities, faculty-level jobs lacking the possibility of tenure have risen from 55% of new hires in 1989 to 70% today. The probability that a Ph.D. recipient under 35 will obtain a tenure-track job has fallen from 10% in 1993 to 7% in 2003.

These trends have made job competition among young scientists "very Darwinian," stated Norka Ruiz Bravo, deputy director for intramural research at NIH. Tenure-track openings routinely attract scores or even hundreds of applications, several speakers noted. Amidst mountains of resumes, hiring committees of competing research universities vie for the same small group of elite candidates. These few stars each garner multiple interviews and job offers while many of their fellow applicants count themselves lucky to receive a form rejection letter. Sometimes, in fact, departments that fail to land their top choice leave tenure-track positions unfilled rather than hire from a slightly lower echelon.

Immense cost and risk for universities

This apparently paradoxical situation arises from the merciless economics of competition for NIH R01 grants, which several participants termed the "holy grail" of scientific survival. "Big salary differences" separate tenure-track and non-tenure-track positions, Stephan noted. That differential pales, however, beside the truly immense cost--and therefore the immense risk--that universities must shoulder to outfit new assistant professors for the big-time funding fray. Start-up costs for new tenure-track faculty members--which must be footed by the university several years before many novice assistant professors can realistically be expected to bring in significant grant money--average $300,000 at public universities and $400,000 at private ones, Stephan said. But they can go much higher--to $1 million or more, according to Robert Goldman, chair of cell and molecular biology at the Feinberg Medical School at Northwestern University, who recounted spending $3 million to hire two faculty members.

These arrangements, Goldman added, assume that NIH will begin picking up some of the costs within 3 years, an eventuality far from guaranteed for young investigators without demonstrated success winning R01 grants. Indeed, Goldman noted, hiring a proven senior researcher away from another university is often a better economic bet than launching even an apparently stellar novice. The initial investment for the established investigator is higher, but "not that much higher," and an "immediate transfer" of his or her funding soon follows, Goldman explained.

Creating opportunities for increased scientific independence among non-tenure-track scientists will therefore require a variety of new arrangements, concluded a breakout discussion led by Susan Gerbi, George Eggleston Professor of Biochemistry at Brown University. Complicating the picture, she noted, is the wide range of job situations found in that catch-all category, including, among others, former postdocs who have stayed on as staff researchers in a mentor's lab, scientists running facilities that service a number of investigators, and trailing spouses of tenure-track faculty who are working on their own projects. No data currently details this varied group's characteristics.

Clearly, though, the need for space and facilities, which NIH demands and institutions would have to finance, is a major obstacle to any effort to provide these scientists a degree of independence. In some cases, Gerbi suggested, PIs can solve the problem by providing staff scientists space and time to work on their own projects within the PI's lab. She, for example, has made just such an arrangement with a longstanding staffer of her own lab. But such a setup, she continued, keeps the staff scientist at the mercy of the PI's career moves, including retirement, relocation to another university, or loss of the PI's grant funding.

University-run "incubator" facilities providing space and various centralized services could also equip non-tenure-track scientists for independent research in the absence of large grants, suggested Christopher Espenshade, assistant professor of cell biology at Johns Hopkins University. But, warned Philip Clifford, associate dean for postdoctoral education at the Medical College of Wisconsin, the departmental divisions within universities could make such facilities difficult to establish and run. And to compete successfully for grants, Gerbi noted, nontenured scientists would need ways of convincingly demonstrating that their proposed work will be truly their own and not a "backdoor" means for PIs' labs to receive additional grants. Study sections would also have to take non-tenure-track scientists' beginner status into account in rating their proposals, the group agreed.

The entire committee will have to struggle with the issue of non-tenure-track scientists as it prepares its report, agreed Thomas Cech, president of the Howard Hughes Medical Institute and chair of both the committee and the workshop. Increasing interdisciplinary work, the growth of team science, and economic pressures following the end of NIH's "doubling" are among the forces bringing important changes to university science, he noted. Finding ways to meet the needs of non-tenure-track scientists and make the best use of their talents and skills will doubtlessly challenge not only Cech's committee but many others for some time to come.

Beryl Lieff Benderly writes from Washington, D.C.