Personal and social norms in a multilevel public goods experiment

In this study we provide a novel measurement of personal normative beliefs, empirical expectations and normative expectations in the multilevel public goods game. The objective is twofold. On the one hand, we aim at investigating whether personal and social norms are reactive to variations in the relative efficiency of the public goods. On the other hand, we aim at understating which kind of norm better explains contribution to both the public goods. In our online experiment, personal norms, as elicited by personal normative beliefs, play a crucial role. They are both more reactive to efficiency gains and more in line with contribution decisions as efficiency increases. However, social norms, as elicited by empirical expectations and normative expectations, still anchor contribution decisions to social expectations, especially when the efficiency of the related public good is relatively low. Moreover, we highlight a norm spillover effect among the public goods with the empirical expectations concerning one good impacting (negatively) the contribution to the other public good. This result reveals how norms referred to alternative reference networks may interact with each other and possibly conflict.