An Agent-Based Model of a Mobile Phone Production, Consumption and Recycling Network

Abstract

This chapter introduces an agent-based model of material flow networks associated with mobile phones, including production, consumption and recycling. Against a background of impending metal scarcity and growing stocks of metal waste, the case study explores the development of “closed-loop” flow systems for metals in mobile phones. Agents in the developed model are designed to represent actors in the mobile phone life-cycle, including manufacturers, consumers, refurbishers and recyclers. Via interaction with one another, these agents trade metals, mobile phones and mobile phone components, ultimately giving rise to a network of transactions. The structure of this network is an emergent property of agent decision-making and of environmental variables such as metal prices and demand growth. The aim of the modelling exercise is to gain insight into how adjustments in agent decision-making and in these environmental variables can lead to greater cyclicality of metal flows at the emergent system level. The model introduces several innovations relative to the previous cases described in this book. The first of these innovations is the implementation of goods as discrete entities with unique properties, rather than continuous flows of uniform quality. This enables agents to do detailed analyses of individual goods—in this case mobile phones—in the process of taking decisions about purchasing, processing and investments. A second novel feature of the model lies in the relationship between the model code and the ontology. Unlike previous cases, communication between these two components takes the form of a continuous dialogue rather than being a one-off occurrence at initialisation. This is essential to enabling the representation of mobile phones as discrete entities and also allows for richer data analysis and simplified verification procedures.