On page 68 I learned that one reason (though hardly the only reason) why US university labs rely more on grad students and postdocs while Europeans rely more on staff scientists and similar sorts of personnel is that in the 1980's NSF started pushing faculty to put grad students on their grants rather than technicians. I suspect that part of the reason was economic, but only partly so: While a grad student will just about always receive less in salary and benefits than a technician (especially an experienced technician), some universities charge massive tuition for grad students and that tuition then gets covered by the research grant supporting the student. Consequently, while at some schools the economics will favor the use of students by a wide margin, at others the margin may not be quite as wide. Moreover, depending on their level of training, level of experience, personal abilities, and opportunities for development, a technician may be more useful than a grad student--the grad students may ultimately go farther as scientists, but it takes a while to get them there, whereas a good technician can keep a project moving forward on a consistent basis. I suspect that part of the reason for NSF's preference is that they have long had a mandate to expand the scientific workforce because of an alleged crisis in STEM, and supporting students will do that, whereas supporting technicians will simply keep the labs humming along and producing mere science. And this focus on students apparently started in the 1980's, which is when "A Nation At Risk" came out.
(And let me assure you that I don't buy into a dichotomy: Clearly the world needs good lab techs AND students training to be scientists, but the answer then is to fund projects that have people in whatever mix of roles makes sense for the success of the project, not a mandate to endlessly expand the STEM workforce.)
ADDENDUM: I decided to look for the original source for the assertion about NSF. It's a 1998 interview with then-NSF Director Rita Colwell by Science magazine. Here's the key quote:
On a recent report of a Ph.D. glut in the life sciences:
In the 1980s, NSF asked investigators to put graduate students on their research budgets, saying that it preferred to fund graduate students rather than technicians. But as often happens, the pendulum swung too far. There needs to be a balance. Well-trained technicians are needed to run equipment and labs, and what better way to provide opportunities for them than to build it into research grants.
There's great respectability for those who want to be technicians, but we don't give them the opportunity. We've made it a sign of failure if you don't get a Ph.D. Other countries don't have this [negative] attitude. … With all the emphasis on graduate students, I'm not so sure that the question we're facing is one of overproduction. I think we have to look more closely at how we're using our resources. We've created a situation in the career pipeline where there is a bulge at the end of a postdoc and no place to go.Even in 1998, people were talking about PhD gluts. All of this has happened before and will happen again. Of course, that was around the time that NIH doubled its research spending, so for a while things were good for life sciences PhDs. But exponential growth can only go on for so long.