Overton Leadership: Shifting Legitimacy Boundaries as a Strategic Capability in Complex Adaptive Systems

Purpose: This article develops a novel theory of Overton Leadership, conceptualizing leadership as the strategic management of legitimacy boundaries in complex adaptive systems. It addresses a critical gap in leadership theory: how leaders expand the range of perceived acceptable strategic options under conditions of institutional constraint and normative resistance. Design/Methodology/Approach: The study adopts a theory-building approach integrating institutional theory, complexity leadership, strategic framing, and legitimacy scholarship. A dynamic conceptual model is developed specifying core constructs, structural relationships, and formal propositions. The framework is expressed through a longitudinal equation model enabling empirical operationalization. Findings: We theorize that Overton Leadership operates through narrative reframing and stakeholder cognitive realignment, resulting in legitimacy window expansion and strategic option growth. Organizational trust moderates reframing effectiveness, while environmental volatility accelerates legitimacy shifts. The model distinguishes leadership that adapts within constraints from leadership that redefines constraints. Theoretical Contributions: The article contributes to leadership theory by: (1) Reframing leadership as legitimacy-boundary management; (2) Extending institutional entrepreneurship through a leader-centric dynamic model; (3) Formalizing legitimacy expansion as a measurable rate-of-change construct; (3) Integrating narrative framing into dynamic systems modeling. Practical Implications: In AI governance, ESG transitions, and digital platform regulation, leaders must strategically expand normative acceptance before implementing transformative strategies. Overton Leadership provides a systematic framework for managing such shifts. Originality/Value: This is the first formal theory positioning leadership as the dynamic expansion of the legitimacy window. It introduces a measurable construct of legitimacy shift and establishes a foundation for longitudinal empirical testing across organizational, technological, and governance domains.