Tourism carrying capacity as dynamic property of complex socio-ecological systems

Overtourism is not just overcrowding: it is a systemic imbalance sustained by feedbacks between visitors, residents’ welfare, the performance of local facilities, and environmental quality. Tourism carrying capacity sits at the centre of overtourism research and policy, yet it is still commonly operationalised as static visitor limits, implicitly assuming that thresholds could be set without accounting for the feedbacks they are meant to regulate. Here we introduce a minimal dynamical model that retains the essential feedbacks through which residents, tourists, economic capital, and environmental quality co-evolve. From this model, a formal definition of tourism carrying capacity emerges as a state-dependent quantity shaped by economic conditions, environmental quality, and social responses, and tempered by congestion and competitive pressure. Crucially, capacity alone is a weak planning target: sustainability depends on the long-run regime selected by the coupled system, and on how that regime shifts under perturbations. A bifurcation analysis of policy-relevant parameters maps tipping points and the resulting regime structure, from stable coexistence to multistability and sustained oscillations, including overtourism outcomes where tourism and capital persist while residents and environmental quality collapse. Overall, the results clarify, in a unified and rigorous setting, why capacity thresholds may inadequately reflect the dynamic complexity of tourism systems, and how integrated dynamical analyses can inform more robust policy design.