A market-based approach to allocation at open-loop recycling

Changes in the amount of recycled material delivered by, or used in, the life cycle of a product will affect the environmental burdens of other product life cycles. These indirect effects can potentially be taken into account through expansion of the system investigated to include the activities affected. Presently, the assessment of the indirect effects is often based on inaccurate assumptions. The indirect effects depend on, e.g. how the market for the recycled material reacts to a change in the supply of, or demand for, the recycled material. This, in turn, depends on political constraints, price elasticities, etc, in the markets for recycled material. This paper presents a model that takes the market aspects into consideration. It can be used in a life cycle assessment (LCA) to model the indirect effects either through system expansion or as a basis for allocation. It is designed for the use in change-oriented LCAs, but it can also be used in accounting type LCAs. The model is demonstrated in two theoretical cases: increased local collection for recycling of old corrugated containers and newsprint, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.