Top Research Productivity and its Persistence∗ A Survival Time Analysis for a Panel of Belgian Scientists

Work still very much in progress- Please do not quote The paper contributes to the debate on cumulative advantage effects in academic research, by examining top performance in research productivity and its persistence over time, using a panel dataset comprising the publications of biomedical and exact scientists at the KU Leuven in the period 1992-2001. More particularly, we study (i) the selection of researchers into productivity cohorts: top, medium and non-performers and (ii) analyse how they switch between these categories over time. The data set allows controlling for several factors that are expected to play a role in scientific publication activity, such as gender, age, cohort, tenure and promotion, hierarchical position and seniority, correcting for a.o. scientific discipline, full-time position, teaching load. We find that productivity cohorts are generally persistent over time. About one quarter of the scientists in the sample achieves top performance at least once in the observation period, with five out of a hundred scientists being persistently top. Analyzing the selection and hazard to first and subsequent top performance, shows strong support for an accumulative process with rank