Figure 5

Stratification of career movement.

(a) The matrix of probability to have a transition from rank i to rank j, (1 being the top institution) indicates that most movements involve elite institutions (rank is small) while transitions between bottom institutions are rather rare. (b) The likelihood M(i, j) for a move to take place by accounting for the size of the institutions is characterized by a high degree of stratification in institutional rankings. Indeed, we observe two distinct clubs (red regions), indicating that the overrepresented movements are the ones within elite institutions (lower-left corner) or within lower-rank institutions (upper-right corner) and scientists belonging to one of the two groups tend to move to institutions within the same group. (c) – (d) The Likelihood M(i, j)|Δc* < 0 and M(i, j)|Δc* > 0 for transitions resulting in higher and lower scientific impact, respectively, indicates that the stratification in career moves is robust against individual performance. We find the red region in lower-left corner is more concentrated in Fig. 5d than in c, hinting that being more mobile in the space of rankings may lead to variable performance.