Strategy Department, Kellogg School of Management, Northwestern University, Evanston, IL 60208.
Northwestern University Institute on Complex Systems and Data Science, Evanston, IL 60208.
Proc Natl Acad Sci U S A. 2019 Jul 9;116(28):13885-13890. doi: 10.1073/pnas.1812341116. Epub 2019 Jun 24.
Scientists and inventors increasingly work in teams, raising fundamental questions about the nature of team production and making individual assessment increasingly difficult. Here we present a method for describing individual and team citation impact that both is computationally feasible and can be applied in standard, wide-scale databases. We track individuals across collaboration networks to define an individual citation index and examine outcomes when each individual works alone or in teams. Studying 24 million research articles and 3.9 million US patents, we find a substantial impact advantage of teamwork over solo work. However, this advantage declines as differences between the team members' individual citation indices grow. Team impact is predicted more by the lower-citation rather than the higher-citation team members, typically centering near the harmonic average of the individual citation indices. Consistent with this finding, teams tend to assemble among individuals with similar citation impact in all fields of science and patenting. In assessing individuals, our index, which accounts for each coauthor, is shown to have substantial advantages over existing measures. First, it more accurately predicts out-of-sample paper and patent outcomes. Second, it more accurately characterizes which scholars are elected to the National Academy of Sciences. Overall, the methodology uncovers universal regularities that inform team organization while also providing a tool for individual evaluation in the team production era.
科学家和发明家越来越多地以团队形式工作，这引发了关于团队生产性质的基本问题，使得个体评估变得越来越困难。在这里，我们提出了一种描述个体和团队引文影响力的方法，该方法既在计算上可行，又可以在标准的大规模数据库中应用。我们通过合作网络追踪个体，定义个体引文指数，并研究个体单独工作或团队合作时的结果。通过研究 2400 万篇研究论文和 390 万项美国专利，我们发现团队合作比单独工作具有显著的优势。然而，这种优势随着团队成员个体引文指数之间的差异的增大而下降。团队的影响力更多地由低引文的团队成员而不是高引文的团队成员来预测，通常集中在个体引文指数的调和平均值附近。与这一发现一致的是，团队倾向于在科学和专利的所有领域中，由具有相似引文影响力的个体组成。在评估个体时，我们的指数考虑了每个合著者，与现有指标相比具有显著优势。首先，它更准确地预测了样本外论文和专利的结果。其次，它更准确地描述了哪些学者被选为美国国家科学院院士。总的来说，该方法揭示了团队组织的普遍规律，同时为团队生产时代的个体评估提供了一种工具。
