Ecological Economics 41 (2002) 109 – 123 ANALYSIS A time use perspective on the materials intensity of consumption Mikko Jalas * Department of Management, Helsinki School of Economics and Business Administration, PO Box 1210, FIN-00101 Helsinki, Finland Received 4 September 2001; received in revised form 29 January 2002; accepted 31 January 2002 Abstract The ecological requirements to drastically increase the productivity of materials use call for improvements in the efficiency of consumption. This (eco-)efficiency discussion often takes a functional view on consumption, noting that present consumption is inefficient and that it is not the products that the consumers want, but the services that the products yield. However, contemporary consumption serves many needs that are not functional and universal, but subjective and obscured from the producers. This paper develops a time use approach towards consumption, which makes allowance for the subjectivity of needs, while still enabling the analysts to approach the concept of a sustainable lifestyle. A distinctive premise of the analysis is that it assumes time and money not to be interchangeable and consumption to be limited by available consumption time instead of purchasing power. This approach is demonstrated by linking the direct and the indirect energy use of Finnish two-person households to the data of a national time use survey. The results are used to point out some of the potential time use rebound effects of such new eco-efficient services that transfer activities from private households to the market actors. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Consumption; Time use; Rebound effect; Services This article is also available online at: www.elsevier.com/locate/ecolecon 1. Introduction The current discussion on eco-efficiency often calls for improvements in the efficiency of con- sumption. Such ideas are manifested in the claims that it is not the products that consumers want, but the services that the products yield (e.g. Schmidt-Bleek, 1994; Meijkamp, 1998). These thoughts reflect earlier discussions on the ultimate source of utility taken up by, for example, Lan- caster (1966) who proposed that preferences are expressed in terms of product characteristics, which are available in different combinations from different products. Consumers, according to Lancaster, need information and managerial skills to find the efficient product combinations. As such, this discussion is also relevant for the present debate on eco-efficiency in which both producers and consumers are urged to question the products as the ultimate source of utility and welfare (Lintott, 1998). * Fax: +358-9-43138777. E-mail address: jalas@hkkk.fi (M. Jalas). 0921-8009/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved. PII:S0921-8009(02)00018-6