Abstract
Many multifunctional products, e.g. smartphones, have been put on the market in recent years. Multifunctional products have the potential to replace more than one single-function products and thus may contribute to dematerialization. Meanwhile, the spread of such products may also lead to an increase of material use and stocks by creating new markets. This study estimated material stocks of consumer durables in Japan on a function basis and discussed the potential contribution of multifunctional products to dematerialization. The products selected for the study were cloth washer-dryers and smartphones. The results showed that washer-dryers have replaced in-use washing machines and a large part of in-use drying machines. The spread of smartphones also led to the decrease in in-use conventional mobile phones; however, it did not decrease in-use portable digital audio players and compact digital cameras, function of which can be replaced by smartphones. The results indicate multifunctional products can replace single-function products with primary functions of the multifunctional products, but they do not necessarily replace single-function products with other functions. This suggests that there may be cases where the spread of multifunctional products increase material use and stocks if the multifunctional products use more materials than the conventional single-function products.
