Consumer's behaviour in assessing environmental impact of consumption : state of the art and challenges for modelling consumer's behaviour in life cycle based indicators

The European Commission (EC) has been developing an assessment framework to monitor the evolution of environmental impact associated to the European Union (EU) consumption. The assessment framework should help to support a wide array of policies, such as those related to resource efficiency, eco-innovation and circular economy. The environmental impact of EU consumption is assessed adopting two sets of life cycle-based indicators: the Consumption footprint and the Consumer footprint, which have a complementary role in assessing those impacts. The EU Consumer Footprint is the measurement of the environmental impacts based on the life cycle assessment (LCA) of products (or services) purchased and used in one year by an EU citizen. This is based on the results of LCAs of representative consumed products (and services, where relevant). Within the framework of this project, a dedicated area of research focused on the "Product use phase and consumption scenarios", aiming at the examination of consumer behaviour types in view of further refinement of product use phase modelling and in support to the definition of scenarios on improved environmental behaviours. Whereas the production-based perspective helps in identifying domestic sectors, product groups and products responsible for emissions and resource use, the consumption-based perspective looks at the overall environmental impact induced by the domestic consumption. Each of the two perspectives on environmental impact has its use for policy-makers. This report is addressing variability in the use phase grounded on consumers' actual behaviour patterns, with reference to the aims presented before. After a brief review of theories and models explaining consumer behaviours, this report discusses the main approaches for measuring the environmental impacts of consumption and the key drivers that influence consumers' shift towards more envrionmentally friendly consumption choices and behaviours. Moreover, the possible link between behavioural sciences and Life Cycle Assessment, through the development of scenarios on consumer behaviour applied to the Basket of Products (BoPs) is discussed, together with the possibility to capture the rebound effects in these scenarios. Current knowledge gaps and related research needs are illustrated in the concluding section, highlighting possible future paths of research for the integration of behavioural economics into environmental assessment (e.g. to capture the rebound effects induced by household expenditure structure shifting, based on Engel's curve), and to complement and further improve the approaches discussed herein.