Informal connections outweigh coauthorship ties in academic impact.

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 [Formula: see text] political science articles authored by [Formula: see text] 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.