Agent-based modeling of the diffusion of environmental innovations — An empirical approach

This paper presents an agent-based model of the diffusion of water-saving innovations. The empirical foundation of this model is a study, which was carried out for that specific purpose. As an example case, the diffusion of three water-related innovations in Southern Germany was chosen. The model represents a real geographic area and simulates the diffusion of showerheads, toilet flushes, and rain-harvesting systems. Agents are households of certain lifestyles, as represented by the Sinus-Milieus® from commercial marketing. Agents use two different kinds of decision rules to decide upon adoption or rejection of the modeled innovations: A cognitively demanding deliberate decision rule and a very simple decision heuristic. Thus, the model integrates concepts of bounded rationality. The overall framework for decision-making is the Theory of Planned Behavior, which has been elaborated using innovation characteristics from diffusion research. The model was calibrated with empirical data stemming from a questionnaire survey and validated against independent data. Scenarios for the nearer future show that water-saving innovations will diffuse even without further promotion, and different promotion strategies that relate specifically to both innovations and lifestyles can be pointed out.