Abstract：Under causation logics, crossing legitimacy threshold is an outcome achieved by making rational choices with a goal-oriented mindset. However, effectuation logics imply that it can also be an improvisational effect based on a mean-oriented mindset. Using a single case study of a high-tech new venture, this study reveals the spiral dynamics of effectuation and causation in the process of crossing legitimacy thresholds. At product innovation stage, crossing the latent legitimacy threshold is an effectual effect and a by-product of innovation. It starts with available means and progresses by obtaining self-commitment of stakeholders through communication and social interaction. At commercialization stage, crossing the explicit legitimacy threshold is an achieved goal by adopting rational legitimation strategies including performing on different stages and sensemaking with storytelling and identity claim. At growth stage, crossing legitimacy threshold is a process combining effectuation with causation.
