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Rise of the temporary workforce

People leaving

A growing number of scientists publish once and disappear from the record, suggesting that they have left academia.Credit: Getty

Recent decades have been marked by a surge in ‘short-term scientists’ who publish at least once but soon stop contributing to the literature. That’s the conclusion of an analysis of astronomy and ecology journals going back to the early 1960s. The authors also examined robotics journals published since the mid-1960s and observed a similar effect. The analysis, published in the Proceedings of the National Academy of Sciences, found that the average “half-life” of a science career — the time it takes for half the researchers of a given cohort to cease producing papers — has dropped from 35 years in the 1960s to only 5 years in the 2010s1.

The study also found a strong trend towards an increased number of “supporting authorships” — postdocs, staff scientists and other non-senior researchers who provide specialized skills but do not lead publications. Only about 40% of ecology and astronomy researchers in cohorts from the 2010s had ever been listed as a lead author on a paper. In the mid-1960s, that rate was about 80%. Author position matters: in each field examined, researchers who fail to become lead authors within the first five years of their careers are significantly more likely to leave academia.

Given the rise in the past couple of decades in ‘team science’ — large collaborations that are often assembled across multiple disciplines — ‘support’ or temporary researchers, including postdocs, are essential to the production of knowledge today, says study co-author Staša Milojević, an informatics researcher at Indiana University Bloomington. “Yet there are no mechanisms for allowing them more secure job prospects,” she notes.

The paper offers a fresh perspective on a familiar challenge in academia: the fact that the number of PhD degrees awarded outpaces the number of available tenure-track or tenured academic positions. The odds of securing tenure drop with each additional postdoc, especially if the researcher is not a lead author, says Milojević. Despite significant links between an author’s early productivity and ultimate academic survival, the study found neither productivity, nor citation impact, nor level of initial collaboration proved reliable predictors of career longevity.

The American Association of University Professors (AAUP) in Washington DC calls for an increase in the number of available tenure-track positions. “If people are doing real science or science teaching, they ought to be tenured or eligible for it,” says Greg Scholtz, director of the AAUP’s department of academic freedom, tenure and governance. “We need to talk about this topic more, and think of ways to assist people in having productive careers in their chosen fields,” he says.

Milojević advocates policy changes at US universities and elsewhere to create a more secure scientific workforce. She says that institutions should consider increasing the number of permanent staff positions or levelling off the number of PhD students that they accept. Furthermore, she says, departments, principal investigators and universities should create reward and evaluation systems that are specific to temporary and support scientists that better assess and recognize their contributions to the research enterprise.

Nature 566, 287 (2019)



  1. 1.

    Milojević, S. et al. Proc. Natl Acad. Sci. USA 115, 12616–12623 (2018).

    PubMed  Article  Google Scholar 

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