This paper reports the results of a ‘probabilistic dictator game’ experiment in which subjects were given an option to share chances to win a prize with a dummy player. Using a within-subject design we manipulated two aspects of the decision, the relative cost of sharing and the nature of the lottery: the draws were either independent for the two players (‘noncompetitive’ condition) or one's success meant other's failure (‘competitive’ condition). We also asked for decisions in a standard, non-probabilistic, setting. The main results can be summarized as follows: first, a substantial fraction of subjects do share chances to win, also in the competitive treatments, thus showing concern for the other player that cannot be explained by outcome-based models. Second, subjects share less in the competitive treatment than in other treatments, indicating that procedural fairness alone cannot explain the data. Overall, these results suggest that models aiming at generalizing social concerns to risky environments will have to rely on a mix of distributive and procedural fairness.

We investigate the external validity of giving in the dictator game by using the misdirected letter technique in a within-subject design. First, subjects participated in standard dictator games (double blind) conducted in labs in two different studies. Second, after four to five weeks (study 1) or two years (study 2), we delivered prepared letters to the same subjects. The envelopes and the contents of the letters were designed to create the impression that they were misdirected by the mail delivery service. The letters contained 10 Euros (20 Swiss Francs in study 2) corresponding to the endowment of the in-lab experiments. We observe in both studies that subjects who showed other-regarding behavior in the lab returned the misdirected letters more often than subjects giving nothing, suggesting that in-lab behavior is related to behavior in the field.

We investigate the role of intentions in two-player two-stage games. For this purpose we systematically vary the set of opportunity sets the first mover can choose from and study how the second mover reacts not only to opportunities of gains but also of losses created by the choice of the first mover. We find that the possibility of gains for the second mover (generosity) and the risk of losses for the first mover (vulnerability) are important drivers for second mover behavior. On the other hand, efficiency concerns and an aversion against violating trust seem to be far less important motivations. We also find that second movers compare the actual choice of the first mover and the alternative choices that would have been available to him to allocations that involve equal material payoffs.

Our paper reconsiders the triadic design proposed by Cox (Games and Economic Behavior 46:260–281, 2004) to identify trust and reciprocity in investment games. Specifically, we extend the design in two directions. First, we collect information on investors’ choices by using both the direct-response (as does Cox) and strategy methods. Using the latter, we are able to condition reciprocity on initial inequality, which is endogenous when investigating reciprocity. We demonstrate that the triadic design provides evidence for reciprocity once that initial inequality is considered. Second, we elicit expectations and test their coherence with the triadic outcomes. By examining the relationship between trust actions and expected gains, we analyze whether investors’ expectations are consistent with their behavior. Finally, we test for the existence of an emotional bias, i.e., whether expectation mismatches induce trustees to change actual choices from the planned ones.

Other-regarding preferences are important for establishing and maintaining cooperative outcomes. In this paper, we study how the formation of other-regarding preferences during childhood is related to parental background. Our subjects, aged 4–12 years, are classified into other-regarding types based on simple binary-choice dictator games. The main finding is that the children of parents with low education are less altruistic, more selfish, and more likely to be weakly spiteful. This link is robust to controlling for a rich set of children’s characteristics and class fixed effects. It also stands out against the overall development of preferences, as we find children to become more altruistic, less selfish, and less likely to be weakly spiteful with increasing age. The results, supported by a complementary analysis of World Values Survey data, suggest an important role of socialization in the formation of other-regarding preferences.

This paper theoretically and experimentally investigates the impact of information provision on voluntary contributions to a linear public good with an uncertain marginal per-capita return (MPCR). Uninformed donors make contribution decisions based only on the expected MPCR (i.e. the prior distribution), while informed donors observe the realized MPCR before contributing. The theoretical analysis predicts that the impact of information on average contributions crucially depends on the generosity level of the population, modeled as a stochastic change in the pro-social preferences. In particular, a less generous population increases contributions substantially in response to good news of higher than expected MPCR and reduces contributions relatively little in response to bad news of lower than expected MPCR. The opposite is true for a more generous population. Thus, the theory predicts that information provision increases (reduces) average contributions when the population is less (more) generous. This prediction finds strong support in a two-stage lab experiment. The first stage measures subjects’ generosity in the public good game using an online experiment. The resulting measure is used to create more and less generous groups in the public good lab experiment, which varies the information provided to these groups in the lab. The findings are in line with the theoretical predictions, suggesting that targeted information provision to less generous groups may be more beneficial for public good contributions than uniform information provision.

Using data aggregated from seven papers that study repeated play in standard ultimatum games with either stranger or absolute stranger matching, we show that the behavior of responders changes with experience. High offers are more likely to be accepted with experience and low offers are more likely to be rejected. At the individual level, there is a negative relationship between the likelihood that a given offer is accepted and the size of the preceding offer. We compare the results with predictions generated by static models of distributional preferences, implicitly dynamic models of preferences with reciprocity, and explicitly dynamic models of adaptive learning. The data is most consistent with models of preferences with reciprocity.

We examine choices in two-player extensive-form games that give subjects opportunities for individualistic as well as other-regarding behavior, and where each subject makes choices in a variety of games. Following an extensive search over models, where we estimate a single parameter vector for all the games rather than different parameter vectors for each game, we find that (1) the level-n model organizes the data well, (2) other-regarding behaviors in these games appear to consist primarily of egalitarian and utilitarian behaviors, and (3) there is no significant evidence for reciprocal behavior.

This paper examines two strands of literature regarding economic models of cooperation. First, payoff transformation theories assume that people may not be exclusively motivated by self-interest, but also care about equality and fairness. Second, team reasoning theorists assume that people might reason from the perspective of the team, rather than an individualistic perspective. Can these two theories be unified? In contrast to the consensus among team reasoning theorists, I argue that team reasoning can be viewed as a particular type of payoff transformation. However, I also demonstrate that many payoff transformations yield actions that team reasoning rules out.