The picture that emerges of the causes of productivity is complex. There are clearly many interacting factors that contribute to research productivity. Research group size or access to resources is just one, which on the evidence available, may not be very important. Explanations of research performance must take into account personal (individual) and structural (environmental factors), and the interaction between them.
1. How is research productivity related to the phases of a research career?
Researchers’ scientific productivity increases as they attain higher academic position. Two other individual-level factors are also consistently found to be related to research productivity: researchers’ age (curvilinear relationship) and education background
2. Which research-group level factors affect individuals’ careers and research productivity?
Scientists backed up by many PhD-students/assistants/technicians are more productive. Group leader’s experience and status along with strong leadership and good atmosphere is positively related to individuals’ productivity. Larger group size is, at least in natural sciences, also positively related to productivity.
3. How is group composition and resources of PhD-students research groups related to their future careers?
I have not been able to find much relevant previous research on PhD students specifically. Most of the studies have focused on researchers in general and this is reviewe below.
4. Can research productivity, seen in relation to total resources for research, be increased by having resources redirected from PhD-students to senior researchers and to technical/administrative personnel?
I have not been able to find much relevant previous research on this issue. However, one can make some deductions from previous findings. It is well established that PhD students are much less productive in terms of number of publications than more established researchers. Moreover, supervising of PhD students may be time-consuming for the professors. Thus, hiring more experienced researchers instead of PhD students is likely to contribute to improved productivity of a research group. Nevertheless, PhD students are important work force in the science system and do a lot of the time-consuming experimental work. More of this work would then have to be done by the experienced researchers themselves, which will reduce their publication output. This is also confirmed in previous research: Professors with many PhD students are more productive than professors with few PhD-students.