Indirect reciprocity and strategic reputation building in an experimental helping game

We study indirect reciprocity and strategic reputation building in an experimental helping game. At any time only half of the subjects can build a reputation. This allows us to study both pure indirect reciprocity that is not contaminated by strategic reputation building and the impact of incentives for strategic reputation building on the helping rate. We find that pure indirect reciprocity exists, but also that the helping decisions are substantially affected by strategic considerations. Finally, we find that strategic do better than non-strategic players and non-reciprocal do better than reciprocal players, casting doubt on previously proposed evolutionary explanations for indirect reciprocity.     

Reciprocity and Giving in a Consecutive Three‐Person Dictator Game with Social Interaction

We study pure indirect reciprocity by setting up a modified dictator game with three players A, B, and C acting sequentially. Subject A takes a share of a pie and passes the rest to subject B, while B divides the rest between herself and C. We find that this consecutive three‐person dictator game increases generosity compared with the traditional two‐person dictator game. We analyze the influence of social interaction and uncertainty. In treatments with certainty we observe pure indirect reciprocity: B indirectly reciprocates for A's behavior in the decision on how generous to be to C.     

Favor trading in public good provision

Favor trading is common. We do something nice for someone and they do something nice in return. Several motives might underlie such behavior, including altruism, strategic motives, and direct or indirect positive reciprocity. It is not yet well-understood how these fit together to affect behavior, how they interact in various institutional structures, and how they play out over time. We use a laboratory experiment to study the elements and dynamics of favor trading in a particular setting: the private provision of a public good. In our experiment, giving subjects the ability to practice targeted reciprocity by making a simple, low-cost change in information provision increases contributions to the public good by 14 %. Subjects reward group members who have previously been generous to them and withhold rewards from ungenerous group members. Strategic concerns cannot explain all of this behavior, and it must be at least partly due to direct reciprocity. When someone cannot directly benefit from favor trading, he gives much less to the public good. People thus excluded from the “circle of reciprocity” provide a clean and strict test of indirect reciprocity. Contrary to previous studies in the literature, we do not observe indirect reciprocity.     

Dissertation abstract: Experiments on fairness and reputation

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 essay¹ 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. JEL Classification C70, C91, D63, D64 ¹Co-authored with Ninghua Du. Dissertation Committee: Dissertation Advisor: James C. Cox Martin Dufwenberg, Price V. Fishback, Ronald L. Oaxaca     

Social preferences and moral biases

An emerging consensus in economics is that three motives are at work in strategic decisions: distributive preferences, reciprocal preferences and self-interest. An important obstacle, however, has been moral biases: distortions created by self-interest can obscure our measures of social preferences. This paper describes a simple experiment to address this. We compare the decisions of implicated “stakeholders” with those of impartial “spectators.” We find that stakeholders are less inclined to respond to the generosity of others than are spectators. We also clarify a result in previous research [e.g., Offerman, T., 2002. Hurting hurts more than helping helps. European Economic Review 46, 1423–1437] that stakeholders punish unkindness more than they reward kindness. We find that this asymmetry in reciprocity has two sources: an asymmetry in the underlying preference that even impartial spectators display and a moral bias; stakeholders punish more and reward less than spectators. In sum, we find that all three motives have important and significant effects on final allocations.     

Trust and trustworthiness reputations in an investment game

Trust is an essential component of good social outcomes and effective economic performance. Reputation on the trusteeʼs past behavior in the same role has proven to be greatly effective at raising the level of trust. In this study, we show that providing information on the trusteeʼs past behavior as the trustor is equally effective as a reputation system. In fact, people still find it worthwhile to invest in a reputation as a trusting person, even though the immediate payoff for trusting is poor. This confirms the role of indirect reciprocity as a strategic notion based on reputation, whereby pro-social actions by one person towards a second person are sanctioned by a third party.     

The tragedy of the commons revisited: The importance of group decision-making

We use a laboratory experiment to compare the way groups and individuals behave in an inter-temporal common pool dilemma. The experimental design distinguishes between a non-strategic problem where players (individuals or groups of three) make decisions without interaction and a strategic part where players harvest from a common pool. This allows us to correct for differences between individuals and groups in the quality of decisions when testing for differences in competitiveness. Group decisions are either made by majority rule or unanimity. The results show that groups are less myopic than individuals (i.e., they make qualitatively better decisions) but that they are more competitive than individuals when placed in a strategic setting. The net result for groups deciding by majority rule is that they make less efficient decisions in the strategic game than individuals do. We are able to show that this is caused by the median voter departing from her original preference in early periods with a shrinking pool. When groups have to make unanimous decisions they start playing the strategic game more efficiently then individuals do, but they rapidly become more competitive with repetition of the game.     

Separating reputation, social influence, and identification effects in a dictator game

This study explores the ways in which information about other individual's action 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 is an important step in trying to understand how impulses towards selfish or generous behavior arise. The statistical analysis of experimental data reveals that the reputation effects have a stronger impact on dictators’ actions than the social influence and identification.     

Social status and group norms: Indirect reciprocity in a repeated helping experiment

In the economic literature, reciprocity is typically studied in situations of repeated interaction between two individuals. It refers to one individual rewarding kind acts of the other or punishing hostile acts. In contrast, this paper studies indirect reciprocity, where a cooperative action is rewarded by a third actor, not involved in the original exchange. We provide experimental evidence on indirect reciprocity. The experiment is based on the ‘repeated helping game’ developed by Nowak and Sigmund (J. Theoret. Biol. 194 (1998) 561; Nature 393 (1998) 573), involving random pairing in large groups. Pairs consist of a donor and a recipient. Donors decide whether or not to provide costly ‘help’ to the recipients they are matched with, based on information about the recipient's behavior in encounters with third parties. We observe clear evidence of indirect reciprocity. Many decision-makers respond to the information about previous decisions (whether or not to help others) of the recipients. In our experiments, this indirect reciprocity is largely based on norms about how often the recipient should have helped others in the past. We show that these norms develop similarly within groups of interacting subjects, but distinctly across groups. This leads to the emergence of group norms.     

Do people make strategic commitments? Experimental evidence on strategic information avoidance

Game theory predicts that players make strategic commitments that may appear counter-intuitive. We conducted an experiment to see if people make a counter-intuitive but strategically optimal decision to avoid information. The experiment is based on a sequential Nash demand game in which a responding player can commit ahead of the game not to see what a proposing player demanded. Our data show that subjects do, but only after substantial time, learn to make the optimal strategic commitment. We find only weak evidence of physical timing effects.     

Social Preferences in the Lab: A Comparison of Students and a Representative Population

We report from a lab experiment conducted with a sample of participants that is nationally representative for the adult population in Norway and two student samples (economics students and non‐economics students). The participants make choices both in a dictator game (a non‐strategic environment) and in a generalized trust game (a strategic environment). We find that the representative sample differs fundamentally from the student samples, both in the relative importance assigned to different moral motives (efficiency, equity, and reciprocity) and in the level of selfish behavior. It is also interesting to note that the gender effects observed in the student samples do not correspond to the gender effects observed in representative sample. Finally, whereas economics students behave less pro‐socially than non‐economics students, the two student groups are similar in the relative importance they assign to different moral motives.     

Sophisticated Experience-Weighted Attraction Learning and Strategic Teaching in Repeated Games

Most learning models assume players are adaptive (i.e., they respond only to their own previous experience and ignore others' payoff information) and behavior is not sensitive to the way in which players are matched. Empirical evidence suggests otherwise. In this paper, we extend our adaptive experience-weighted attraction (EWA) learning model to capture sophisticated learning and strategic teaching in repeated games. The generalized model assumes there is a mixture of adaptive learners and sophisticated players. An adaptive learner adjusts his behavior the EWA way. A sophisticated player rationally best-responds to her forecasts of all other behaviors. A sophisticated player can be either myopic or farsighted. A farsighted player develops multiple-period rather than single-period forecasts of others' behaviors and chooses to “teach” the other players by choosing a strategy scenario that gives her the highest discounted net present value. We estimate the model using data from p-beauty contests and repeated trust games with incomplete information. The generalized model is better than the adaptive EWA model in describing and predicting behavior. Including teaching also allows an empirical learning-based approach to reputation formation which predicts better than a quantal-response extension of the standard type-based approach. Journal of Economic Literature Classification Numbers: C72, C91.     

Good standing and cooperation

Indirect reciprocity is generally considered one of the leading mechanisms to explain how cooperation may emerge by natural selection. The basic intuition is that establishing a reputation of being a helpful individual increases the probability of being in turn helped. Two models have been proposed to describe how indirect reciprocity may work: the standing model (Sugden 1986/2004 in The economics of rights, cooperation and welfare. Blackwell, Oxford.) and the image-scoring model (Nowak and Sigmund 1998a in Nature 393:573–577, b in J Theoretical Biol 194:561–574). Although there is evidence that the former model would perform better under a wide set of circumstances, it is often maintained that it requires individuals with an implausibly large capacity of processing recursive information. In this paper, I argue that this is not actually the case. I further emphasize that even if the hypothesis of indirect reciprocity is unable to give a fair account of the ecological bases of cooperation, it has inspired a deal of research precious to social sciences.     

Why Any Seatbelt Mandate is an Infinitely Iterated Prisoner’s Dilemma: A Health Economics Perspective

Abstract

Among the most controversial of public health measures are those that restrict people’s freedom of choice presumably for the purpose of protecting their own health and safety. Mandatory use of automobile seatbelts can inspire allusions to the “tyranny of health” and the ‘health police.” This study revisits state seatbelt legislation, which is in force in all but one state of the USA. In modeling seatbelt mandates as indefinitely repeated Prisoner’s Dilemma (PD) games, the study qualifies and overcomes the limitations of conventional interest group and expressive voting theories. It indicates why and how utility-maximizing players, particularly carmakers, insurance companies, consumer advocates and regulators, may choose to cooperate, even in instances where mutual defection would bring each of them higher payoffs. The study suggests why state seatbelt mandates endure, despite ongoing concerns that they undermine individual autonomy or that their social costs outweigh the benefits of law-enforcement. The evolution and mediating effects of reputation and reciprocity in otherwise highly contestable healthcare decisions are consequently explored. Finally, the study identifies the implications of indefinitely repeated games on the continuing nature of strategic relationships and for mitigating conflict over traffic safety regulation, regardless of time and place.     

Indirect higher order beliefs and cooperation

This study experimentally examines the role of indirect higher order beliefs in sequential psychological games. We consider a three-player sequential game in which the first and third players do not interact sequentially, but only through an intermediary, the second player. We posit that the third player’s decision to cooperate depends on his indirect higher order belief, namely, his belief about what the first player believes the second player would choose. We employ pre-play communication between the first and third players as a way to influence the third player’s indirect higher order belief. The evidence demonstrates that communication can effectively induce cooperation from the third player by shaping his indirect higher order belief.     

Reciprocity, Trust, and Payoff Privacy in Extensive Form Bargaining

We report decision making in two-person extensive form game trees, using six treatments that vary matching protocol, payoffs, and payoff information. Our objective is to examine game theoretic hypotheses of decision making based on dominance and backward induction in comparison with the culturally or biologically derived hypothesis that reciprocity supports more cooperation than predicted by game theory. We find strong support for cooperation under complete information, even in single-play treatments and in games of trust, unreinforced by the prospect of punishment for defection from reciprocity. Only under private information do we observe strong support for noncooperative game theory.Journal of Economic LiteratureClassification Numbers: C78, C92.     

Peer pressure,social spillovers,and reciprocity: an experimental analysis

This study examines whether reciprocity is affected by what others know and do. Two types of social effects are investigated within the framework of a modified investment game. On the one hand, we assess the role played by the awareness that own choices are observed by another trustee—i.e., peer pressure. On the other hand, we measure the interaction between trustees’ choices—i.e., social spillovers. We find that peer pressure fosters reciprocity and, to a lesser extent, so do social spillovers.     

Knowledge Market Design: A Field Experiment at Google Answers

In a field experiment at Google Answers, we investigate the performance of price‐based online knowledge markets by systematically manipulating prices. Specifically, we study the effects of price, tip, and a reputation system on both an answerer's effort and answer quality by posting real reference questions from the Internet Public Library on Google Answers under different pricing schemes. We find that a higher price leads to a significantly longer, but not better, answer, while an answerer with a higher reputation provides significantly better answers. Our results highlight the limitation of monetary incentives and the importance of reputation systems in knowledge market design.     

Identifying the structure of knowledge networks in the US mobile ecosystems: patent citation analysis

With the emergence of smartphones, the paradigm of the mobile ecosystem has changed rapidly. In particular, global mobile firms focus on technological competition when jostling for market position in recognition of the strategic need to secure a strong mobile platform. In this paper, we analyse the network structure of technological knowledge flows in mobile ecosystems using US patent citation information. We find that two subsectors, platform providers and application and software providers, are at the centre of knowledge exchange activity and play a brokerage role as the key knowledge mediator. Then, we categorise mobile firms into five different groups based on the patterns of their network centrality: knowledge keystone players, knowledge-distributing mediators, knowledge-absorbing mediators, catch-up players, and pure knowledge receivers. The categorisation of firms demonstrates that knowledge flows in the mobile industry converge towards a few leading firms, and such patterns are shaping the mobile ecosystem with respect to technological knowledge. The firms categorised as catch-up players have played a brokerage role within their group, while the firms categorised as knowledge keystone players play a brokerage role across different groups.     

Strategic approximations of discontinuous games

An infinite game is approximated by restricting the players to finite subsets of their pure strategy spaces. A strategic approximationof an infinite game is a countable subset of pure strategies with the property that limits of all equilibria of all sequences of approximating games whose finite strategy sets eventually include each member of the countable set must be equilibria of the infinite game. We provide conditions under which infinite games admit strategic approximations.