A Vensim system dynamics model of the fast-fashion industry, built to identify leverage points for policy intervention in consumer demand, resource consumption, and environmental impact.
How do the interconnected systemic dynamics within the fast fashion industry, driven by consumer behavior and influenced by existing policy interventions, contribute to environmental degradation — and what alternative, holistic systems-based interventions can be identified and evaluated to more effectively mitigate these impacts?
The fast-fashion industry (SHEIN, Temu, Zara, and others) contributes an estimated 8–10% of global GHG emissions, consumes roughly 93 billion m³ of water annually, and generates 92 million tons of textile waste — driven by ultra-low prices and condensed production cycles. The model links three interacting systems:
- Consumer adoption — modeled via the Bass diffusion process (advertising, contact rate, and word-of-mouth driving adoption over time), rather than treating demand as static
- Item consumption rate — how adoption translates into actual purchasing behavior
- Environmental impact stocks and flows — GHG emissions, water usage/pollution, and waste generation, accumulating as a function of the above
Demographic assumptions are benchmarked to the EU market (ages 18–35, ~€1,500 median income, 3–4 purchases/month), using Inditex as an industry proxy. Current sustainability policies (brand transparency, circularity initiatives, sustainable product options) are modeled explicitly and evaluated for effectiveness rather than assumed to work.
- Consumer adoption dynamics have a significant impact on the overall environmental load within the next 4 years
- Current fast-fashion sustainability policies are inefficient at reducing waste generation
- Policies focused on extending average item lifespan and enhancing consumer awareness are the most effective levers for reducing average GHG emissions
- Average consumption rate per adopter and word-of-mouth adoption are identified as the critical drivers of overall system behavior
finalprojectenvfile.mdl— the Vensim system dynamics model (stocks, flows, and causal structure)Fast_Fashion_Analysis.pdf— the full written analysis, literature review, and results
Vensim (system dynamics simulation) · Bass diffusion modeling