Abstract:Open innovation, as a novel paradigm of innovation, calls for deeper exploration of how it can be effectively leveraged. Both inbound and outbound open innovation were examined to assess their distinct impacts on firm performance and underlying mechanisms. The empirical results indicate that, firstly, inbound open innovation has a positive effect on firm performance, while outbound open innovation shows an inverted U-shaped relationship with firm performance, indicating a threshold effect. Secondly, in terms of mechanisms, inbound open innovation primarily enhances firm performance by improving agile R&D capabilities, while outbound open innovation does so by strengthening agile commercialization capabilities. Thirdly, firm size moderates the effects of both types of open innovation. It positively moderates the relationship between inbound open innovation and performance, and also strengthens the inverted U-shaped relationship between outbound open innovation and performance. These findings enrich the understanding of different open innovation types and offer insights into achieving effective, open, and autonomous innovation.