There is plenty of demand for PhD students and fresh postdocs. They help the Prof. with her teaching load, grant writing, etc. They are dedicated, work long hou

There is plenty of demand for PhD students and fresh postdocs. They help the Prof. with her teaching load, grant writing, etc. They are dedicated, work long hours and cost little. There is however, much lower demand for PhDs who would wish to run their own research program, after all the PI can take the same ideas and work and do it under guise of their own research program without giving too much credit to the grad student or postdoc. The result, at least in biomedicine, is an increase in the size of research groups, and very protracted postdoctoral periods.