Extended Producer Responsibility: Waste Hierarchy Flow Simulator

This simulator renders the waste hierarchy as a physical stepped pyramid — Reduce at the narrow top, Landfill at the wide base — and streams a continuous flow of end-of-life product particles through it. Where each particle lands is not scripted: it is sampled from a multinomial logit discrete-choice model, the standard tool environmental economists use to predict how producers and waste handlers actually route material once fees and subsidies change the relative cost of each option. Raise the Extended Producer Responsibility fee and watch the fee-funded subsidy pull mass up and away from Landfill and Recover; raise the eco-design score and see Reuse and Recycle become cheaper on their own merits; lower the collection rate and a share of the stream leaks out before it ever reaches a bin. Live readouts track landfill diversion, a circularity index, and the cumulative EPR revenue funding the whole system.