Beyond intensity of use

Declining intensity of metal use along with a slowdown in world economic growth caused a downward shift in the growth of demand for many metals in the early 1970s. While the traditional intensity-of-use literature focuses primarily on changes in the product composition of income to explain trends in intensity of use, recent empirical evidence, much of which is found in other articles in this issue of Materials and Society, indicates that changes in the material composition of products, caused largely by new technology and material substitution, is also important, and perhaps even more important. Since the product composition of income is heavily influenced by consumer preferences and the demand side of the market while the material composition of products is the result of production technology and the supply side of the market, we need to look beyond intensity of use and assess the relative importance of these two determinants of intensity of use in order to understand fully the slowdown in long-run growth trends since the 1970s. Such an understanding is necessary before we can hope to forecast accurately future metal-consumption trends. 10 references.