This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also by the intention underlying this action. The theory...

We report the results of voluntary contributions experiments where subjects are randomly assigned different rates of return from their private consumption. These random assignments are changed round to round, enabling the measurement of individual player contribution rates as a function of that...

The exogenous manipulation of choice architectures to achieve social ends ('social nudges') can raise problems of effectiveness and ethicality because it favors group outcomes over individual outcomes. One answer is to give individuals control over their nudge ('self-nudge'), but the trade-offs...

In this paper, we investigate the joint influence of empirical and normative expectations on cooperative behavior. We conduct two experimental studies (n = 243) in which we separately elicit (i) behavior in a public goods game and (ii) social norms under the form of normative and empirical...