We use a simple laboratory experiment to measure the effect on altruism of (i) whether the participants’ choices are presented verbally or non-verbally, and (ii) whether the participants have a large amount of loose change. We find strong evidence for the first effect and weaker evidence for the second. These effects may explain some of the variation in the average level of generosity found in different Dictator Game results.

In this study, we report experimental results on the dictator decision collected in two neighboring ethnic minority groups, the matrilineal Mosuo and the patriarchal Yi, in southwestern China. We follow the double-blind protocol as in Eckel and Grossman (in Handbook of experimental economics results, 1998), who find that women in the U.S. donate more than men. We find this pattern reversed in the Mosuo society and find no gender difference in the Yi society. This is highly suggestive that societal factors play an important role in shaping the gender differences in pro-social behavior such as dictator giving.

Many prior studies have identified that subjects in experiments demonstrate preferences for fair allocations. We present an experimental study designed to test whether a similar concern for fairness manifests itself when the decision maker is choosing among differing probabilistic allocation mechanisms that will all generate an ex post unfair allocation by assigning an indivisible prize to one individual. This investigation is inspired by Karni and Safra (Econometrica, 70, 263-284, 2002) in which a structure for preferences for fairness in such an environment was developed. Here we use this model to design experiments that allow us to test for the presence of concern for fairness in individual choice behavior and examine some factors that may affect the intensity of the concern for fairness.

It has recently been argued that giving is spontaneous while greed is calculated (Rand et al., in Nature 489:427–430, 2012). If greed is calculated we would expect that cognitive load, which is assumed to reduce the influence of cognitive processes, should affect greed. In this paper we study both charitable giving and the behavior of dictators under high and low cognitive load to test if greed is affected by the load. This is tested in three different dictator game experiments. In the dictator games we use both a give frame, where the dictators are given an amount that they may share with a partner, and a take frame, where dictators may take from an amount initially allocated to the partner. The results from all three experiments show that the behavioral effect in terms of allocated money of the induced load is small if at all existent. At the same time, follow-up questions indicate that the subjects’ decisions are more impulsive and less driven by their thoughts under cognitive load.

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 conducted a laboratory experiment to study the effects of communication in a dictator game, while maintaining subjects’ anonymity. In the experiment, the recipient has an opportunity to state a payoff-irrelevant request for his/her share before the dictator dictates his/her offer. We found that the independence hypothesis that voice does not matter is rejected. In particular, if the request is for less than half of the pie, the dictator's offer increases as the recipient's request increases. Additionally, there is no dictator who is other-regarding and, at the same time, does not react to the recipient's request.

We report the results of experiments that test for behavioral differences between volunteer subjects recruited in the usual way and pseudo-volunteer subjects in experiments conducted during class time. In a series of dictator games, we find that psuedo-volunteers are more generous on average than their volunteer counterparts, and that non-monetary factors such as religious or altruistic preferences have a greater effect on the giving behavior of pseudo-volunteers.

In this paper we use experimental data from rural Cameroon to quantify the effect of social distance on trust and altruism. Our measure of social distance is relevant to everyday economic interactions: subjects in a Trust Game play with fellow villagers or with someone from a different village. We find that significantly more money is sent when the players are from the same village. Other factors that influence transfers at least as much as the same-village effect are gender, education and membership of rotating credit groups. To test whether Senders are motivated by altruism, they also play a Triple Dictator Game. Senders transfer significantly more money on average in the Trust Game than in the Triple Dictator Game. However, there is also a social distance effect in the Triple Dictator Game. Results from a Risk Game suggest that Trust Game transfers are uncorrelated with attitudes to risk.

We experimentally investigate to what extent people trust and honor trust when they are playing with other people’s money (OPM). We adopt the well-known trust game by Berg et al. (in Games Econ. Behav. 10:122–142, 1995), with the difference that the trustor (sender) who sends money to the trustee (receiver) does this on behalf of a third party. We find that senders who make decisions on behalf of others do not behave significantly different from senders in our baseline trust game who manage their own money. But receivers return significantly less money when senders send a third party’s money. As a result, trust is only profitable in the baseline trust game, but not in the OPM treatment. The treatment effect among the receivers is gender specific. Women return significantly less money in OPM than in baseline, while there is no such treatment effect among men. Moreover, women return significantly less than men in the OPM treatment.

Standard economic theories assume that people are self-interested and their wellbeing solely dependent on their own material gains or losses. Unless they have an impact on monetary payoffs, the perceptions of anonymous individuals are irrelevant to people’s decision making. However, a large body of research in sociology and social psychology demonstrates that self-identity is developed through one’s understanding of how one is perceived by others. Using (Cooley’s, Human nature and the social order, 1964) concept of the “looking-glass self” as a framework, we evaluate experimentally whether or not people care about the imputed judgment of anonymous others arising from their imagination of their perceptions. We implemented variants of the Becker–DeGroot–Marschak mechanism to elicit the monetary value attached to the perceptions by participants. In one variant, only nonnegative bids were allowed, while in another, negative bids were allowed. We show that in an environment in which the perceptions of others are only conveyed to participants anonymously and privately, self-interested individuals exhibited strong negative perception avoidance even though the perceptions have no impact on their monetary payoff. The participants were willing to spend a significant amount in order to avoid confirming the supposedly negative perception. Thus, for them, ignorance was truly bliss. We also show that, in the absence of the audience effect, the fair-minded participants adopted a neutral attitude towards the perception of them as fair.

We conduct a representative dictator game in which students and random members of the community choose both what charity to support and how much to donate to the charity. We find systematic differences between the choices of students and community members. Community members are much more likely to write in their own charity, community members donate significantly more ($17), on average, and community members are much more likely (32%) to donate the entire $100 endowment. Based on this evidence, it does not appear that student behavior is very representative in the context of the charitable donations and the dictator game.

A growing number of experimental studies focus on the differences between the lab and the field. One important difference between many lab and field experiments is how the endowment is obtained. By conducting a dictator game experiment, we investigate the influences of windfall and earned endowment on behavior in the laboratory and in the field. We find subjects donate more in both environments if the endowment is a windfall gain. However, although the experimental design was intended to control for all effects other than environment, there are significant differences in behavior between the lab and the field for both windfall and earned endowment. This points to the importance of discussing the context when interpreting both laboratory and field experiment results as well as when conducting replication studies.

The three dissertation essays investigate different aspects of reputation in games where fairness is an important consideration. The first essay studies the effects of reputation on indirect reciprocity in different dictator games. The first experiment places dictators in two environments where they can either give money to the paired player or take money away from them: in one treatment the paired player is a stranger and in the other treatment the dictator has information on the paired player's reputation. Contrary to anecdotal evidence, the statistical tests show that the dictators’ behavior towards a stranger is not statistically significantly different from their behavior towards an individual with an established reputation. The findings arise because a high proportion of dictators acted purely in their own self interest in both treatments. The data also provides evidence that dictators are more generous when they know that their choices (but not their identities) will be revealed in the future. In the second experiment the dictators’ choices were restricted to only generous actions. In such environment the dictators sent more money on average to recipients with a reputation for being generous than to recipients without a reputation.

The second essay explores the ways in which information about others’ actions affects one's own behavior in a dictator game. The experimental design discriminates behaviorally between three possible effects of recipient's within-game reputation on the dictator's decision: reputation causing indirect reciprocity, social influence, and identification. The separation of motives helps to identify the mechanisms of social transmission of impulses towards selfish or generous behavior. The data analysis reveals that the reputation effects have a stronger impact on dictators’ actions than social influence and identification.

In the third essay we examine the reputation effects in a labor market setting by analyzing the influence of negative technological shocks on long run relationships between firms and workers. The positive correlation between wage and effort in static conditions has been demonstrated in many experimental studies and has been one of the prominent explanations for the existence of wage rigidity. We subject these findings to further tests in a non-stationary environment that better corresponds to outside-the-lab market conditions. We observe the positive correlation of wages and effort but do not find support for downward wage rigidity in our data. Once the shocks occur, firms lower the wages and relationships often break down. The workers who accept a lower wage respond with exerting a lower effort.

Can we use the lens of dual-system theories to explain altruistic behavior? In recent years this question has attracted the interest of both economists and psychologists. We contribute to this emerging literature by reporting the results of a meta-study of the literature and a new experiment. Our meta-study is based on 22 experimental studies conducted with more than 12,000 subjects. We show that the overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero. One reason for this null result could be that promoting intuition has heterogeneous effects on altruism across different subgroups of subjects or contexts. Another reason could be that there simply is no real effect and that previously reported single results are false positives. We explore the role of heterogeneity both by performing a mediator analysis of the meta-analytic effect and by conducting a new experiment designed to circumvent the issue of potential heterogeneity in the direction of the effect of promoting intuition. In both cases, we find little evidence that heterogeneity explains the absence of an overall effect of intuition on altruism. Taken together, our results offer little support for dual-system theories of altruistic behavior.

Over the last 25 years, more than a hundred dictator game experiments have been published. This meta study summarises the evidence. Exploiting the fact that most experiments had to fix parameters they did not intend to test, in multiple regression the meta study is able to assess the effect of single manipulations, controlling for a host of alternative explanatory factors. The resulting rich dataset also provides a testbed for comparing alternative specifications of the statistical model for analysing dictator game data. It shows how Tobit models (assuming that dictators would even want to take money) and hurdle models (assuming that the decision to give a positive amount is separate from the choice of amount, conditional on giving) provide additional insights.

We show that, if giving is equivalent to not taking, impure altruism could account for List’s (in Journal of Political Economy 115(3):482–493, 2007) finding that the payoff to recipients in a dictator game decreases when the dictator has the option to take. We examine behavior in dictator games with different taking options but equivalent final payoff possibilities. We find that recipients tend to earn more as the amount the dictator must take to achieve a given final payoff increases, a result consistent with the hypothesis that the cold prickle of taking is stronger than the warm glow of giving. We conclude that not taking is not equivalent to giving and agree with List (in Journal of Political Economy 115(3):482–493, 2007) that the current social preference models fail to rationalize the observed data.

We use time, rather than money, as the salient component of subjects’ incentives in three workhorse experimental paradigms. The use of waiting time can be interpreted as a special type of real effort condition, in which it is particularly straightforward to achieve experimental control over incentives. The three experiments, commonly employed to study social preferences, are the dictator game, the ultimatum game and the trust game. All subjects in a session earn the same participation fee, but their choices affect the time at which they are permitted to leave the laboratory. Decisions that are associated with greater own payoff translate into the right to depart earlier. The modal proposal in both the dictator and ultimatum games is an equal split of the waiting time. In the trust game, there is substantial trust and reciprocity. Overall, social preferences are evident in time allocation decisions. We compare subjects’ decisions over time and money and find no significant differences in average decisions. The pattern of results suggests that results obtained in the laboratory with money as the medium of reward generalize to other reward media.

Many previous experiments document that behavior in multi-person settings responds to the name of the game and the labeling of strategies. With a few exceptions, these studies cannot tell whether frames affect preferences or beliefs. In three large experiments, we investigate whether social framing effects are also present in Dictator games. Since only one of the subjects makes a decision, the frame can affect behavior merely through preferences. In all the experiments, we find that behavior is insensitive to social framing. We discuss how to reconcile the absence of social framing effects in Dictator games with the presence of social framing effects in Ultimatum games.

This paper analyzes if men and women are expected to behave differently regarding altruism. Since the dictator game provides the most suitable design for studying altruism and generosity in the lab setting, we use a modified version to study the beliefs involved in the game. Our results are substantial: men and women are expected to behave differently. Moreover, while women believe that women are more generous, men consider that women are as generous as men.

Psychological games of guilt aversion assume that preferences depend on (beliefs about) beliefs and on the guilt sensitivity of the decision-maker. We present an experiment designed to measure guilt sensitivities at the individual level for various stake sizes. We use the data to estimate a structural choice model that allows for heterogeneity, and permits that guilt sensitivities depend on stake size. We find substantial heterogeneity of guilt sensitivities in our population, with 60% of decision makers displaying stake-dependent guilt sensitivity. For these decision makers, we find that average guilt sensitivities are significantly different from zero for all stakes considered, while significantly decreasing with the level of stakes.