The young and the old, the fast and the slow: a large-scale study of productivity classes and rank advancement

We examined a large sample of Polish science, technology, engineering, mathematics, and medicine (STEMM) scientists (N = 16,083) to study rank advancement and productivity in the past 40 years. We used two previously neglected time dimensions – promotion age and promotion speed – to construct individual lifetime biographical and publication profiles. We followed a classificatory approach and the new methodological approach of journal prestige–normalized productivity. All scientists were allocated to different productivity, promotion age, and promotion speed classes (top 20%, middle 60%, and bottom 20%). The patterns found were consistent across all disciplines: scientists in young promotion age classes (and fast promotion speed classes) in the past were currently the most productive. In contrast, scientists in old promotion age classes (and slow promotion speed classes) in the past were currently the least productive. In the three largest disciplines, the young-old promotion age productivity differential for associate professors was 100–200% (150–200% for full professors), and the fast-slow promotion speed productivity differential for associate professors was 80–150% (100–170% for full professors). Our results were partly supported by a regression analysis in which we examined odds ratio estimates of belonging to top productivity classes. To examine the sample, we combined biographical and demographic data collected from the national register of all Polish scientists and publication metadata on all Polish articles indexed in Scopus (N = 935,167).