The environmental potential of reuse: an application to used books

Reuse is generally considered to have environmental benefits, but it has not yet been widely adopted in environmental policy or strategy. In this paper, a simple model of second-hand markets is explored with a case study of used books that illustrates the behavior of the model and shows that such a model is consistent with the data. Three questions of the dynamics of reuse are addressed: (1) If it becomes easier to buy and sell used goods (via Internet markets or other means), by how much will sales of used goods increase? (2) When sales of used goods increase, by how much will sales of new goods decrease? (3) When is reuse better than recycling? Expanding from the case study, the model is used to examine how reuse affects the consumption of new goods, and the relative merits of reuse versus recycling. When the used goods market is small, the ratio of the price of used and new goods, an observable quantity, is approximately equal to the fractional decrease in sales of new goods that will result from increased sales of used goods. A formulation of the environmental impact of reuse and recycling is developed that includes the market impact of reuse. Illustrating this formulation for books with a simplified analysis, reuse of books through sales in a second-hand market is estimated to save more than twice as much energy, with considerable uncertainty, than making books from recycled paper. The formulation provides a basis for identifying products and markets for which reuse can be an effective environmental strategy.