The aim of the research was to investigate how to stimulate sustainable consumer behaviors that lead to a lowering of the carbon footprint. Because of environmental challenges at the individual and societal levels, researchers agree that behavioral change is necessary. We argue that when already performing a sustainable behavior, this behavior can spill over to other sustainable actions, even to more difficult ones. First, we studied whether a positive behavioral spillover occurs between product categories and whether the spillover effect depends on the ease or difficulty of the sustainable behavior. Second, we investigated whether high awareness of sustainability determines the spillover between categories. We conducted three online experiments in Central Europe, investigating whether spillover takes place between behaviors assigned to the same category (transport or food) or between behaviors assigned to different categories (transport or food). In all three studies participants had to make two independent decisions. In studies 1a (N=281) and 1b (N=195), the effect of the ease/difficulty of the behavior was tested. In study 2 (N=164), awareness of CO2 emission reducing effects was manipulated. Findings revealed a behavioral spillover between sustainable choices.

<p dir="ltr">This thesis explores various dimensions of strategic communication, cooperation, and information design within economic and organizational contexts. </p><p><br></p><p dir="ltr">Chapter 2 investigates whether the Law Merchant system can enhance cooperation among agents in a repeated interaction setting and how the presence of bribery affects this dynamic. The study finds that the Honest Law Merchant system does not significantly improve cooperation compared to a baseline scenario without such an institution, while the introduction of bribery further diminishes cooperative behavior. These findings suggest that while judicial enforcement mechanisms hold promise for promoting cooperation, their effectiveness can be undermined by corrupt practices. </p><p><br></p><p dir="ltr">Chapter 3 experimentally investigates behavioral spillovers between two social dilemma type games. In our experiments, subjects play Prisoner’s Dilemma game (PD) and Public Goods game (PGG) simultaneously, where the opponents of the two games do not overlap. I vary the level of strategic uncertainty in PD game and test how this affects subject's contributing behavior in PGG, which is held constant across treatments. I find that behavioral spillover exists in our setting and comes in an asymmetric form. When people are in an environment where cooperation is easy to sustain in the PD game, the PGG contributions do not increase much, compared to the baseline treatment when the PGG is played alone. However, when in the setting where cooperation is difficult to sustain in the PD game, PGG contributions decrease significantly.</p><p><br></p><p dir="ltr">Chapter 4, a joint work with Xinxin Lyu, chapter extends the work from Chapter 3 by exploring the differences in between individuals and teams. The study employs the Individual Evolutionary Learning (IEL) model and additional team experimental treatments. Initial results show that teams exhibit higher cooperation and contribution levels compared to individuals, but these advantages diminish over time, particularly in environments with lower strategic uncertainty. The findings provide insights into group dynamics and the challenges teams face in sustaining cooperation, with significant implications for economic and organizational contexts.</p>