The Impact Evaluation of Sustainable Consumption

Putting sustainable consumption into practice is a challenge that requires the effort and coordination of numerous societal domains and actors. The paper deals with the contribution of policy making and policy evaluation. More specifically, it addresses the question of how to evaluate the effectiveness of policy instruments dedicated to rendering household consumption more sustainable. Despite the extensive literature on instrument effectiveness, sustainability assessment, and consumer behaviour, only a few accounts deal with the specific characteristics and impacts of policy instruments for sustainable consumption.

Against this backdrop, a framework is suggested for the ex post analysis of effects resulting from such policy instruments. Instrument effects include changes in consumption patterns (“outcomes”), subsequent changes in the state of the environment, society and/or economy (“impacts”), and side effects. Step-by-step guidance is provided through the evaluation process. The approach helps to assess the extent to which sustainable consumption policy instruments have achieved their stated goals, but also encourages a critical reflection of these goals. In addition to evaluating instrument effects, the framework serves to explain these effects. It does so on the basis of theoretically grounded hypotheses that tackle drivers of and barriers to instrument effectiveness, thus exploring this relatively new policy field. Methodologically, a combination of qualitative methods (narrative reconstruction) and quantitative methods (e.g., material flow analysis) is recommended to causally link policies to changes in consumption patterns and impacts on sustainability.