研究结果

5.1非正式网络比正式网络规模更大、密度更高、层级性更弱

正式与非正式联系所构成的网络存在显著差异。以连通分量数量衡量，致谢网络规模更大、碎片化程度更低。致谢网络的平均连接度大约是合著网络的两倍。约19%的学者在两个网络中均无任何联系，即既无正式合作关系也无非正式致谢关系。两类网络中学者度中心性的相关性为中等水平，说明学者在两种结构中所处的位置并不完全一致。就性别而言，合著网络中的性别差异极小，男女学者的平均中心性相近；但在致谢网络中，男性学者的中心性更高。从图1B和1C可以看出，致谢网络在度分布上层级性更弱，意味着学者之间连接程度的极端差异较少。图1D显示，合著网络中独立学者所发表的文章多为定性研究，相比之下致谢网络中的独立学者在不同论文研究类型中分布更为均衡。

Past work has documented the importance of formal collaboration, particularly coauthorship, in increasing research productivity and innovation. However, we know much less about how informal collaboration relates to publication success. Informal ties facilitate the exchange of intangible resources like mentoring, guidance, and feedback. These interactions form a support structure that aims to improve ideas and facilitate the successful development of research projects. However, these informal exchanges are difficult to measure because they do not leave as clear a trail as coauthorship ties. We uncover this layer of informal communication around scholarly outputs by parsing the information contained in the acknowledgment sections of published articles. Our data include N∼130,000 political science articles authored by N∼86,000 scholars from 2003 to 2023. We analyze scholars’ embeddedness in this informal structure of collaboration and reveal that 1) informal ties create a larger and denser network of support than coauthorship ties; 2) disconnection from informal networks is associated with lower productivity and impact; and 3) informal ties are a more relevant predictor of publication success than formal collaborations (i.e., coauthorship), even after matching for gender, seniority, methodological orientation, geographical location, and institutional prestige. Using coarsened exact matching and random forest regressions, we demonstrate that informal support structures are significantly associated with citation impact, creating gaps in who benefits from these connections.