Four career types
In this first step, we create a typological description of all of the professors’ careers across all cohorts, disciplines, and statuses. We therefore analyzed all 351 careers, calculated the distance matrix, and classified the careers according to a ward-clustering procedure (Fig. 1). The silhouette analysis indicates that four clusters give the statistically most adequate number of solution.
The four distinct clusters are characterized by a specific composition, ordering, and duration of career spells: We call these careers “direct,” “seniority,” “conversion,” and “parallel.” Whereas the career types “conversion” and “parallel” combine spells in the corporate world with spells in academia, “direct” and “seniority” are almost exclusively academic career types.
Direct (n = 148, 42%): The direct type likely corresponds the closest to a collective imaginary of professors’ career and also is the most widespread career type at the EPFL. It starts with an educational period of 8.9 years on average; the highest degree is obtained at 28.9 years on average. This educational phase is then followed by a relatively short pre-tenure phase (7 years on average), which occurs exclusively within academia. At 40 years, 66% of this cluster is already a full professor; at 50 years, this share is 100%. This indicates a relatively quick access to the academic tenure. This spell was followed by a career leap directly from a post-doctoral position to full professorship often without passing through a period of associate professorship (which, on average, is only 1.6 years).
Seniority (n = 87, 25%): The seniority career type is characterized by a rather long pre-tenure phase that follows an educational period of 10.2 years on average. At 40 years, 28% of this group are associate professors and 67% are still occupying post-doctoral positions. Following an associate professorship, the appointment as full professor occurs after 45 years of age. Still, at 50, only half of the individuals hold such a position. This last observation clearly distinguishes this type from direct careers. A rather long period in the pre-tenure phase almost never leads to a full professorship and, if it does, only after a period of an associate professorship.
Conversion (n = 63, 18%): In this cluster, the educational period lasts 7.8 years on average. Following this, however, the members of this type quit academia and work, on average, for 8.6 years in the corporate world. Subsequently, they return to university and are either directly recruited as full professors or pass through a short period of associate professorship (1.9 years) before becoming a full professor. They are not required to earn their way up within the university hierarchy. Rather, they directly convert the practical capital acquired in their corporate career years into a tenured position. At the age of 50, virtually all of those pursuing this type of career have become full professors.
Parallel (n = 53, 15%): The parallel career type starts with the shortest educational period of all types, in most cases followed by a long spell in the corporate world. At 40, 93% of the clusters are holding either positions in the private sector or “mixed” positions combining a professorship and an activity in the corporate world. This second type including extra-academic states differs from the conversion type in two ways: first, the extended period of professional employment in the private sector exhibits a process of accumulated practical capital that is only progressively converted into a professorship. Second, unlike the careers based on conversion, parallel careers lead to lower positions, such as an associate professorship.
Career types according to cohort, discipline, and the place of assistant professorship
This second descriptive part illustrates how these types vary according to cohort, discipline, and the place of assistant professorship. Cohorts illustrate the organizational re-positioning, disciplines underline the differences between “pure” and “applied” sciences, and the place of assistant professorship distinguishes between local and international endowment with scientific capital.
Development of career types according to the nomination cohort
We first consider the global evolution of the career types according to the nomination cohorts. Our results reflect the impact of the organizational changes associated with the transformation in an entrepreneurial university on careers: while the accumulation of scientific capital continues to be valued, the likelihood of being able to convert practical capital into a professorship sharply declines in the last cohort (Fig. 2).
For all three cohorts, direct careers are the most important cluster (between 40 and 45%). It is noteworthy that the transition to an entrepreneurial university (evidenced by the 2010 cohort) has not led to an upsurge of direct careers. Conversion and parallel careers, which both involve extra-academic career spells, are clearly declining from the oldest to the youngest cohort of nomination. In particular, conversion careers, which still add up to a quarter of all careers in the 1980 cohort, decrease in size to only about 5% in the 2010 cohort. Also, the importance of parallel careers decreases steadily between 1980 and 2010, albeit at a slower pace: While they amount to 20% of all careers in 1980, they only add up to 10% in 2010. More and more of these careers combining practical and scientific capital have been replaced by seniority careers, occurring exclusively within academia. Whereas only 10% of the 1980 cohort pursued a seniority career, this value rises to 40% in the 2010 cohort. This finding means that, somewhat counterintuitively, professors’ careers are increasingly based on the slow accumulation of scientific capital.
Career types according to discipline
Second, we consider the distribution of disciplines among career types (Table 3). The professors of basic sciences are overrepresented in the direct careers and underrepresented in the other clusters, especially in conversion careers and parallel careers. The professors of applied disciplines such as civil engineering or mechanical engineering are overrepresented in the practical career types and underrepresented in direct careers.
These descriptive findings seem to confirm what we know about “pure” and “applied” disciplines: While the early display of scientific capital is important for pure science, future professors of applied disciplines are more easily able to convert their experiences in practical domains outside university into positions at the professor level.
Career types and assistant professorships
Finally, we examine whether professors of the four career types were appointed as assistant professors. This finding reveals whether an assistant professorship rather accelerates careers—such as in a direct career—or if it leads to a slow-down of the careers (such as in seniority careers). We distinguish between assistant professorships at the EPFL, in Switzerland, and abroad.
About 75% of all professors have never held a position as assistant professor. Examining the 25% who have, it appears that it is not (only) the position as assistant professor as such that matters. What shapes careers is the place of assistant professorships (Table 4): Whereas those who have been an assistant professor abroad are overrepresented in the direct cluster, those who were in the same position in Switzerland—and to a greater extent, those who were at the EPFL—are overrepresented in the seniority career.
Explaining career types
To consolidate these descriptive analyses, we run four binomial logistic regressions (Table 5). Each model takes the affiliation with a specific cluster as a dependent variable.
The nomination cohorts are important factors for explaining the membership in the seniority and the conversion career, but not for the two others. Compared with the 1980 cohort, we see that the 2000 and 2010 cohorts are positively associated with the seniority type of careers. The chances of professors nominated between 1980 and 2000 to pursue a seniority career are 15% higher than for those nominated between 1969 and 1980. The effect for the 2010 cohort is stronger (35%), meaning that professors nominated under the entrepreneurial university regime are more likely to pursue a rather long period of scientific capital accumulation before the tenure, respectively before getting full professorship. Regarding the conversion career, the 2010 cohort has a strong negative effect with an average marginal effect of − 0.18. The recent organizational reforms seem to lead not only to an increase in the seniority careers but also to a decline in the careers based on the conversion of practical capital, making it less valuable than scientific capital.
The results show more of a disciplinary logic of distinction for the two other career types. Taking basic sciences as reference category, professors of civil and mechanical engineering are significantly underrepresented in direct careers and overrepresented in parallel careers. The average marginal effect of inclusion in the direct cluster is negative for professors of the civil engineering department (− 0.30) or the mechanical engineering department (− 0.22) when comparing with SB. In contrast, being in the civil or mechanical engineering department strongly increases the chance of inclusion in the parallel cluster (32% for civil and 28% for mechanical engineering). These results illustrate that scientific capital is related to basic sciences and direct careers, while practical capital is related to applied sciences and parallel careers. The types “seniority” and “conversion” are hardly correlated with disciplinary logic, but more to institutional transformations measured by the cohorts of nomination.
The regression shows that the assistant professorship abroad has a strong effect on direct careers (35%) and, inversely, has a negative effect on the conversion type (− 0.18). We see that the assistant professorship at the EPFL does not significantly distinguish between career types. However, and not surprisingly, having had an internal career before the tenure professorship increases the chances of belonging to seniority careers by 20%. The introduction of the tenure track model in 2001 has, contrary to its initial purpose, no accelerating effect on professors’ careers. On the contrary, the internal career contributes, to a large extent, to the seniority type.Footnote 8 In this case, an internal assistant professorship rather prolongs the pre-tenure phase and does not work as a career accelerator.