Indicators of Dematerialization and the Materials Intensity of Use

We review the major empirical analyses of the related concepts of dematerialization and intensity of use. Dematerialization refen to the absolute or relative reduction in the quantity of materials used and/or the quantity of waste generated in the production of a unit of economic output A common indicator is the intensity of material use, which is the quantity of material used per unit of economic output. Our discussion focuses on seven topics: the environmental Kuznets curve for materials, material use and long wave theory material decomposition analysis, statistical, inpuboutput and dynamic models of material use, and analyses of national material use. We examine the measurement of aggregate material use and waste emissions, hypothesis testing, the importance of imports, and forces that countervail dematerialization such as rising affluence and the "rebound effect." We conclude that: our knowledge of the extent of and mechanisms behind the patterns of material use are limited largely to individual materials or very specific industries, and most of those examples are metals; the economy is getting "lighter" but the aggregate economic significance of that trend, if any, is unknown; there is no compelling macroeconomic evidence that the US. economy is "decoupled" from material inputs; and we know even less about the net environmental effects of many changes in materials use. We caution against gross generalizations about material use, particularly the "gut" feeling that technical change, substitution, and a shift t o the "information age" inexorably lead to decreased materials intensity and reduced environmental impact. We end with some suggestions for research that may help answer these important questions.     

Individual recognition of contact calls by pygmy marmosets

Individual recognition by voice has been frequently assumed to be an important phenomenon in the social species. The present study on pygmy marmosets (Cebuella pygmaea) demonstrated that there are distinctive acoustic features in each of two contact calls by which individuals could be distinguished from each other. Individual pygmy marmosets responded differently depending on which type of contact call was given and on the identity of the vocalizing animal. Playbacks of individual calls through hidden speakers produced some evidence for differential individual responses, but only when they originated from familiar locations. These results indicate that pygmy marmosets recognize each other on the basis of their contact calls.