How do intra- and inter-organisational collaboration affect research performance? Evidence from German universities

• Denser intra-organisational networks, signaling more collaboration within universities, negatively correlates with their research performance. • Denser inter-organisational networks, signaling more collaboration across universities, negatively correlates with their research performance. • Denser intra- and inter-organisational networks have a positive synergetic effect on the research performance of universities. This paper examines how organisational boundaries shape the relationship between collaboration and research performance in universities. Using meso-level co-authorship networks and matched registry data from 83 German universities between 2006 and 2019, this study advances the understanding of how organisational structures condition collaborative knowledge production and its research performance outcomes. By examining the contingency effects of intra- and inter-organisational networks, we offer new insights into the cost-benefit trade-offs of collaboration, highlighting the importance of balancing internal cohesion with external diversity. While intra-organisational networks reinforce strong relational ties that support existing knowledge, they may constrain the formation of novel knowledge combinations. Conversely, inter-organisational networks expand opportunities for new knowledge combinations, but at the cost of weaker ties, which may reduce the depth and stability of knowledge exchange. Our findings highlight the strategic value of integrating intra- and inter-organisational networks to optimise the research impact of universities.