Ecological Economics 36 (2001) 119–132
Sustainability concepts that rest on the idea of resource- or energy-efficiency improvements due to technological progress tend to overestimate the potential saving effects because they frequently ignore the behavioral responses evoked by technological improvements.
Efficiency improvements also affect the demand for resources and energy, and often an increase in efficiency by 1% will cause a reduction in resource use that is far below 1% or, sometimes, it can even cause an increase in resource use. This phenomenon is commonly labeled the rebound effect, which is well-known among energy economists, but never attracted much attention in ecological economics. The paper starts with the traditional neoclassical analysis of the rebound effect in a partial equilibrium framework that concentrates on the demand of one particular energy service such as mobility or room temperature. It also provides an overview of some of the main empirical studies based on this model that mostly confirm the existence of the rebound effect, but are controversial about its actual importance. However, we have to go beyond the neoclassical single-service model in order to take care of the variety of possible feedback affecting energy use. The paper presents two important expansions of the single-service model in order to show the potential relevance of the rebound effect to ecological economics. First, it is shown that in a multi-services model it proves to be difficult to make general statements about the relevance of the rebound effect. In this case, the overall effect of an increase in energy efficiency on total energy use depends on the on the assumptions about the substitutability between the services considered and the direction of the income effect. Second, the paper also tries to take care of the fact that changes in resource use or energy use are frequently just ‘side-effects’ of other forms of technological progress. Especially technological change of a time-saving nature can have a large influence on energy use as many time-saving devices (for example, faster modes of transport) require an increase in energy consumption that is frequently reinforced by a ‘rebound effect with respect to time’. This effect will be especially strong when wages are high and, at the same time, energy prices are low, as is currently the case in most industrialized countries. Consequently, the paper also provides a strong argument for the introduction of energy taxes.
© 2001 Elsevier Science B.V. All rights reserved.