This study explores the interplay of strategic behaviour and design choices in commons-based innovation, focusing on how contributors use mixed licensing to balance openness with control. Using a dataset from Thingiverse, consisting of 46,530 creative works by 39,942 individuals under 12 intellectual property licenses, we assess how ambivalence introduced by mixed licensing, along with subtractive and additive approaches to innovation, affects the generative capacity of digital commons. A two-level multilevel model tests five hypotheses on remixing, ambivalence, and innovation. Key findings reveal: (1) excessive remixing diminishes generative capacity; (2) ambivalence at the artefact level introduces complexity without fully curbing excessive remixing; (3) ambivalence at the individual level encourages strategic contributions, enhancing generative capacity; (4) artefact-level ambivalence positively moderates additive innovation by fostering strategic engagement; and (5) individual-level ambivalence negatively moderates the additive approach, reflecting tensions between personal interests and collective goals. These findings suggest that mixed licensing serves as both a design and strategic tool for managing private interests and collective goals in digital commons.
