Mental rebound

Current research on causes of rebound effects focus on changes in limiting factors on consumption or production, such as financial or time costs. For instance if the energy efficiency of a car increases, the costs per kilometer also become cheaper and thus consumers might drive longer distances. However, rebound effects due to behavioral changes of households can also be observed for efficiency increases where the costs do not decrease. For instance people driving further with more efficient cars, even though the costs are not lower if higher investment costs are considered. To explain such rebound effects we propose a concept of “mental rebound”. This concept postulates that households apply a mental accounting (bookkeeping) for the environmental impacts caused. The use of higher efficiency, according to our concept, allows households to compensate for this pro-environmental action with an increase in consumption. For instance a buyer of a hybrid car accounts this purchase as a strong reduction in personal environmental impact and hence feels “allowed” to drive more. This report includes a formal description of the mental rebound concept. Based on existing surveys, we evaluate whether a mental rebound can be observed for the purchase of organic food and the absence of a car, In addition, we present the results of a pretest on the rebound effect of more efficient buildings which also provide indications of mental rebound effects. To support the concept of mental rebound, further investigations are needed; with this report we establish a basis for such studies. Although the proposed concept needs further verification, the reflections conducted and the formal evaluations allow some robust policy recommendations