Emotions Enforce Fairness Norms (a Simple Model of Strong Reciprocity)

In experimental games, many subjects cooperate contrary to their material interest and they do that in a reciprocal manner. In addition, many subjects punish those others who behave unkindly, and previous history usually influences subjects’ choices. We propose a simple game-theoretical model to account for these and other experimental phenomena, and compare it with other models of social preferences and reciprocity.Emotions; Fairness; Path-Dependency; Strong Reciprocity; Social Norms

The Power of Words: Why Communication fosters Cooperation and Efficiency

We present a game-theoretical model that accounts for abundant experimental evidence from games with non-binding communication (‘cheap talk’). It is based on two key ideas: People are conditionally averse to break norms of honesty and fairness (i.e., the emotional cost of breaking a norm is low if few people comply), and heterogeneous with regard to their concern for norms. The model explains (a) why cooperation in social dilemmas rises if players can previously announce their intended play, (b) why details of the communication protocol like the number of message senders and the order in which players communicate affect cooperation, (c) why players in sender-receiver games tend to transmit more information than a standard analysis would predict, and (d) why senders of false messages are often sanctioned if punishment is available.Communication; Cooperation; Fairness; Heterogeneity; Honesty; Reciprocity; Social Norms

Do Economists Lie More?

Recent experimental evidence suggests that some people dislike telling lies, and tell the truth even at a cost. We use experiments as well to study the socio-demographic covariates of such lie aversion, and find gender and religiosity to be without predictive value. However, subjects’ major is predictive: Business and Economics (B&E) subjects lie significantly more frequently than other majors. This is true even after controlling for subjects’ beliefs about the overall rate of deception, which predict behavior very well: Although B&E subjects expect most others to lie in our decision problem, the effect of major remains. An instrumental variables analysis suggests that the effect is not simply one of selection: It seems that studying B&E has a causal impact on behavio

Individual Heterogeneity in Punishment and Reward

We design experiments to study the extent to which individuals differ in their motivations behind costly punishment and rewarding. Our findings qualify existing evidence and suggest that the largest fraction of players is motivated by a mixture of both inequity-aversion and reciprocity, while smaller fractions are primarily motivated by pure inequity-aversion and pure reciprocity. These findings provide new insights into the literature on other-regarding preferences and may help to reconcile important phenomena reported in the experimental literature on punishment and reward.Heterogeneity; inequity aversion; monetary punishment/reward; reciprocity; social norms.

Do Economists Lie More?

Recent experimental evidence suggests that some people dislike telling lies, and tell the truth even at a cost. We use experiments as well to study the socio-demographic covariates of such lie aversion, and find gender and religiosity to be without predictive value. However, subjects’ major is predictive: Business and Economics (B&E) subjects lie significantly more frequently than other majors. This is true even after controlling for subjects’ beliefs about the overall rate of deception, which predict behavior very well: Although B&E subjects expect most others to lie in our decision problem, the effect of major remains. An instrumental variables analysis suggests that the effect is not simply one of selection: It seems that studying B&E has a causal impact on behavior.Communication; honesty; lie aversion; major; norms.

Heterogeneous focal points, fairness, and coordination

In games with multiple equilibria, the fairest equilibrium –in case one exists- may be the obvious solution for some players but not for others, and players can be aware of this heterogeneity. This paper theoretically explores how coordination could be achieved in this case. The model is consistent with abundant experimental evidence and explains, for instance, why (a) the attractiveness of the fair equilibrium, (b) out-of-equilibrium payoffs, (c) dominated strategies, and (d) the number of players and available strategies matter for coordination. The model is compared with alternative equilibrium selection criteria like risk and payoff dominance and ideas for new experiments are suggested

Aversion to norm-breaking: a model

This is the author’s version of a work that was accepted for publication in Games and Economic Behavior . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Games and Economic Behavior 64 (2008). DOI http://dx.doi.org/10.1016/j.geb.2007.10.009In experimental games, we observe the following phenomena: (1) many subjects cooperate contrary to their material interest, (2) they cooperate in a reciprocal manner, (3) subjects often punish those others who behave unkindly, and (4) previous history usually influences subjects’ choices. We propose a simple game-theoretical model to account for these and other experimental phenomena, and compare it with other models of social preferences and reciprocity.Ffinancial support from the Spanish Ministry of Education and Science

Emotions enforce fairness norms (a simple model of strong reciprocity)

In experimental games, many subjects cooperate contrary to their material interest and they do that in a reciprocal manner. In addition, many subjects punish those others who behave unkindly, and previous history usually influences subjects’ choices. We propose a simple game-theoretical model to account for these and other experimental phenomena, and compare it with other models of social preferences and reciprocity

On approval and disapproval: theory and experiments

Prior studies have shown that selfish behavior is reduced when co–players have the opportunity to approve/disapprove a player’s choice, even if that has no consequences on the player’s material payoff. Using a prisoner’s dilemma, we experimentally study the causes of this phenomenon, which seems crucial to understand compliance with social norms. Our data is consistent with a model based on the assumption that people feel badly if they expect to be disapproved by others. Furthermore, we find suggestive evidence in line with the following assumptions: (i) People become more aware about the others opinion if feedback is available, and (ii) even if the feedback is ex post and has no effect on their ex ante expectations about disapproval, people prefer not to receive negative feedback

The power of words: why communication fosters cooperation and efficiency

We present a game-theoretical model that accounts for abundant experimental evidence from games with non-binding communication (‘cheap talk’). It is based on two key ideas: People are conditionally averse to break norms of honesty and fairness (i.e., the emotional cost of breaking a norm is low if few people comply), and heterogeneous with regard to their concern for norms. The model explains (a) why cooperation in social dilemmas rises if players can previously announce their intended play, (b) why details of the communication protocol like the number of message senders and the order in which players communicate affect cooperation, (c) why players in sender-receiver games tend to transmit more information than a standard analysis would predict, and (d) why senders of false messages are often sanctioned if punishment is available