1 Alberts, B., Kirschner, M.W., Tilghman, S. & Varmus, H. Proc. Natl. Acad. Sci. USA 111, 5773–5777 (2014).

2 National Institutes of Health. Biomedical Research Workforce Working Group Report http://acd.od.nih.gov/bwf.htm (NIH; 2012).

3 Teitelbaum, M.S. Falling Behind? Boom, Bust, and the Global Race for Scientific Talent (Princeton University Press, Princeton, NJ; 2014).

4 Stephan, P.E. How Economics Shapes Science (Harvard University Press, Cambridge, Mass.; 2012).

5 Stephan, P. Nature 484, 29–31 (2012).

6 National Academy of Sciences. The Postdoctoral Experience Revisited (National Academy Press, Washington, DC; 2014).

7 Stephan, P. & Ma, J. Am. Econ. Rev. 95, 71–75 (2005).

8 Sauermann, H. & Roach, M. Science 352, 663–664 (2016).

9 National Research Council. Trends in the Early Careers of Life Scientists (The National Academies Press, Washington DC; 1998).

10 Marincola, E. & Solomon, F. Mol. Biol. Cell 9, 3003–3006 (1998).

11 National Academy of Sciences. Enhancing the Postdoctoral Experience for Scientists and Engineers: a Guide for Postdoctoral Scholars, Advisers, Institutions, Funding Organizations, and Disciplinary Societies (National Academy Press, Washington, DC; 2000).

12 National Research Council (US). Bridges to Independence: Fostering the Independence of New Investigators in Biomedical Research (National Academies Press, Washington, DC; 2005).

13 National Research Council (US). Research Training in the Biomedical, Behavioral, and Clinical Research Sciences (National Academies Press, Washington, DC; 2011).

14 National Science Board. Science and Engineering Indicators 2008 (National Science Foundation, Arlington VA; 2008).

15 Collins, F. Nature 467, 635 (2010).

16 Freeman, R., Weinstein, E., Marincola, E., Rosenbaum, J. & Solomon, F. Science 294, 2293–2294 (2001).

17 Borjas, G.J. in Science and Engineering Careers in the United States: an Analysis of Markets and Employment, (eds. Freeman, R.B. & Goroff, D.L.) 131–161 (University of Chicago Press, Chicago, IL; 2009)

18 National Science Board Science and Engineering Indicators 2012 (National Science Foundation, Arlington VA; 2012).

19 Garrison, H.H. & Gerbi, S.A. FASEB J. 12, 139–148 (1998).

20 Jones, B.F. Rev. Econ. Stud. 76, 283–317 (2009).

21 Jones, B.F. Rev. Econ. Stat. 92, 1–14 (2010).

22 Jones, B.F. & Weinberg, B.A. Proc. Natl. Acad. Sci. USA 108, 18910–18914 (2011).

23 Sauermann, H. & Roach, M. Science PhD career preferences: levels, changes, and advisor encouragement. PLoS ONE 7, e36307 (2012).

24 Davis, G. Doctors without orders. Am. Sci. 93, supplement http://www.sigmaxi.org/docs/default-source/Programs-Documents/Critical-Issues-in-Science/postdoc-survey/highlights (2005).

25 Davis, G. in Science and Engineering Careers in the United States: An Analysis of Markets and Employment, (eds. Freeman, R.B. & Goroff, D.L.) 99–130 (University of Chicago Press, Chicago; 2009).

26 Su, X. J. Higher Educ. 84, 239–265 (2013).

27 Nerad, M. & Cerny, J. Science 285, 1533–1535 (1999).

28 Levitt, D.G. Careers of an elite cohort of US basic life science postdoctoral fellows and the influence of their mentor's citation record. BMC Med. Educ. 10, 80 (2010).

29 Association of American Universities (AAU). Committee on Postdoctoral Education: Report and Recommendations (AAU, 1998).

30 Association of American Universities (AAU). Postdoctoral Education Survey: Summary of Results (AAU, 2005).

31 The American Medical Association. Requirements for Becoming a Physician (AMA, 2014).

32 Lan, X. J. Policy Anal. Manage. 31, 623–640 (2012).

33 Bonetta, L. The postdoc experience: taking a long-term view. Science http://sciencecareers.sciencemag.org/career_magazine/previous_issues/articles/2010_08_27/science.opms.r1000093 (2010).

35 Stern, S. Do Scientists Pay to be Scientists? National Bureau of Economic Research Working Paper 7410 (1999).

36 Stephan, P. Bioscience 63, 245–246 (2013).

37 Rohn, J. Nature 471, 7 (2011).