This article investigates the decision of consumers at bottle refund machines to either reclaim their bottle deposit or to donate the refund to a non-profit organization. The study documents the unique pre-intervention data on donating behaviour and introduces a field experiment to increase donation levels. The design comprised the strategic framing of the situation by highlighting different cues about the normative, descriptive and local expectations of charitable giving as well as cues about the warm glow of donating money. The experiment took place in 20 supermarkets in Germany and lasted for 12 months. By varying the experimental design and using different modelling approaches, the study arrives at the conclusion that individuals largely act consistent with the assumption having self-regarding preferences that are stable and difficult to change. Hence, our pre-test and postintervention data stand in sharp contrast to results from lab experiments.

The food choices we make every day have a great impact on our environment. Particularly meat consumption significantly contributes to global climate change. Although the current situation calls for a change towards more sustainable diet, meat consumption is still rising. Previous research show that dynamic social norms, i.e. information about ongoing collective behavioral change, can promote pro- environmental behavior, even in the context of meat consumption. Through two pre- registered online experimental studies conducted on a sample of university students (Study 1, N = 227) and on a sample of adult Czech population (Study 2, N = 462), this thesis examines whether dynamic norm message regarding the changing trends in meat consumption can influence intentions to consume less meat. We did not find any direct or total effect of dynamic norms on the preference for meatless meals. Mediation analysis only revealed rather weak indirect effect of dynamic norms on the preference for meatless meals mediated by perceived dynamic norms. In Study 2, we further examined whether the effect of dynamic norm message is conditioned by strength of the dynamic norms (effect of stronger vs weaker dynamic norm) and whether the provision of dynamic norm information triggers self-defense mechanisms which rationalize...