We approach productivity in science in a longitudinal fashion: We track careers over time, up to 40 years. We first allocate scientists to decile-based publishing productivity classes, from the bottom 10% to the top 10%. Then, we seek patterns of mobility between the classes in two career stages: assistant professorship and associate professorship. Our findings confirm that radically changing publishing productivity levels (upward or downward) almost never happens. Scientists with a very weak past track record in publications emerge as having marginal chances of becoming scientists with a very strong future track record across all science, technology, engineering, mathematics, and medicine (STEMM) fields. Hence, our research shows a long-term character of careers in science, with publishing productivity during the apprenticeship period of assistant professorship heavily influencing productivity during the more independent period of associate professorship. We use individual-level microdata on academic careers (from a national registry of scientists) and individual-level metadata on publications (from the Scopus raw dataset). Polish associate professors tend to be stuck in their productivity classes for years: High performers tend to remain high performers, and low performers tend to remain low performers over their careers. Logistic regression analysis powerfully supports our two-dimensional results. We examine all internationally visible Polish associate professors in five fields of science in STEMM fields (N = 4,165 with N art = 71,841 articles).

翻译：我们以纵向方式研究科学领域的生产力：我们追踪了长达40年的科研生涯。首先，我们将科学家按发表成果的生产力划分为基于十分位的等级，从最低的10%到最高的10%。接着，我们探究两个职业阶段——助理教授和副教授期间——不同生产力等级间的流动模式。我们的研究证实，发表生产力水平发生根本性改变（无论是上升还是下降）的情况几乎从未出现。在所有科学、技术、工程、数学和医学（STEMM）领域中，过去发表记录非常薄弱的科学家未来成为发表记录极强的科学家的机会微乎其微。因此，我们的研究表明科学职业生涯具有长期性特征，助理教授阶段的学徒期发表生产力深刻影响着副教授阶段更为独立时期的生产力。我们使用了关于学术生涯的个体层面微观数据（来自国家科学家登记系统）以及关于发表的个体层面元数据（来自Scopus原始数据集）。波兰的副教授往往多年困于其生产力等级：高产出者倾向于在整个职业生涯中保持高产出，低产出者则倾向于保持低产出。逻辑回归分析有力地支持了我们基于二维框架的研究结果。我们考察了STEMM领域五个学科中所有具有国际可见度的波兰副教授（样本量N = 4,165人，对应文章量N_art = 71,841篇）。