Almost two-thirds of chemistry and physics postdoctoral researchers expect to become permanent academics - far more than are ever likely to achieve their ambition.
A report by the Institute of Physics and Royal Society of Chemistry, Mapping the Future: Physics and Chemistry Postdoctoral Researchers' Experiences and Career Intentions, brings together the results of an electronic survey of postdocs in UK chemistry and physics departments.
Nearly 800 responses were received, almost equally split between the two disciplines.
Asked what they were most likely to be doing in six to 10 years, 65 per cent of respondents said "academic on permanent contract".
However, figures cited in the Royal Society's Scientific Century report, published last year, suggest that while 30 per cent of science PhD graduates go on to postdoctoral positions, just 12 per cent of these attain permanent research positions.
The proportions of men and women on their first postdoctoral contract who expect to become permanent academics is almost equal, but the figure for women on their second or subsequent chemistry postdoc falls to 44 per cent, while the figure for male physicists rises to 76 per cent.
The proportion of female chemists whose postdoctoral experience has given them "doubts" about continuing in research doubles from 30 per cent to 61 per cent between first and subsequent contracts.
But Jenni Dyer, diversity programme leader at the IOP, said the report does not recommend specific measures to address female attrition because it is much less of an issue in physics than in chemistry.
The report also eschews calls to improve the job security of postdocs, even though 78 per cent of respondents identified this as the biggest downside of postdoctoral life. But Ms Dyer said at least half of responses had included "diatribes" about job security, which would be digested in a subsequent report.
The report's recommendations largely follow those in the Concordat to Support the Career Development of Researchers, agreed in 2008 between UK universities and funders. These include providing impartial career advice and regular appraisals that give postdocs a realistic sense of their aptitude for an academic career.
According to the report, careers advice has been received by 45 per cent of respondents during their current contract, but it has mostly been delivered by academic staff and only 23 per cent feel they have a good awareness of non-academic career options.
"Some money has been pumped into (researcher career development) but it is still not addressing the issue, which is postdocs' need for better advice on what their other options are when they have finished their contract apart from scrabbling around for another one," Ms Dyer said.
Meanwhile, of the 44 per cent of respondents who have been appraised, a third said it was useful, with many others reporting that their principal investigator had not taken the exercise seriously.
The report also says that only 34 per cent of postdocs in chemistry and 45 per cent of postdocs in physics feel "respected and well regarded" in their departments.