Ranking mobility and impact inequality in early academic careers

TL;DR

This study analyzes ranking mobility and impact inequality among early career academics across 57 disciplines, revealing persistent stability at the extremes, increasing mobility over time, and a decline in impact inequality, informing academic policy.

Contribution

It introduces a comprehensive bibliometric analysis and a simple random walk model to quantify impact ranking mobility and its evolution across multiple disciplines.

Findings

Ranking mobility is low at the top and bottom impact strata.

Mobility of impact rankings has increased over time.

Impact inequality has decreased over the studied period.

Abstract

How difficult is it for an early career academic to climb the ranks of their discipline? We tackle this question with a comprehensive bibliometric analysis of 57 disciplines, examining the publications of more than 5 million authors whose careers started between 1986 and 2008. We calibrate a simple random walk model over historical data of ranking mobility, which we use to (1) identify which strata of academic impact rankings are the most/least mobile and (2) study the temporal evolution of mobility. By focusing our analysis on cohorts of authors starting their careers in the same year, we find that ranking mobility is remarkably low for the top and bottom-ranked authors, and that this excess of stability persists throughout the entire period of our analysis. We further observe that mobility of impact rankings has increased over time, and that such rise has been accompanied by a decline of impact inequality, which is consistent with the negative correlation that we observe between such two quantities. These findings provide clarity on the opportunities of new scholars entering the academic community, with implications for academic policymaking.