Abstract for: Modelling Interdependencies Between Fast and Luxury Fashion: Implications for Sustainability

The fashion industry has been criticized for its substantial environmental pressure. Despite increasing regulations, consumer awareness, and industry initiatives, progress towards sustainability remains limited. Existing literature has generated important insights into sustainable fashion, but it often tends to examine either demand-side drivers or supply-side and operational responses in isolation. Moreover, even within the supply-side literature, fast fashion and luxury fashion are treated as separate isolated empirical contexts. To address the need for systemic understanding of the dynamics within the industry, we use system dynamics modelling. We conceptualize fashion sustainability as a cross-segment system in which fast and luxury fashion co-produce environmental impacts through their intertwined operational decisions. We develop a casual loop diagram drawing on different sources: academic literature and empirical observations obtained from semi-structured interviews with stakeholders across the global supply chain. Preliminary findings reveal that competition between fast and luxury fashion increases speed and waste across the fashion system. Fast fashion’s business model, built on speed, pressures luxury brands to shorten lead times and increase collection frequency, which further intensifies fast fashion responses. This escalation raises forecasting error, excess inventory, material waste, and reinforces a disposability culture among consumers across the industry. This paper contributes a cross-segment causal explanation of fashion unsustainability and treats sustainability outcomes as endogenous to competitive feedback between fast and luxury fashion.It shows that unsustainable outcomes are not produced by one segment alone, but emerge from their interdependencies. to improve clarity and grammar