Rich communication,social motivations,and coordinated resistance against divide-and-conquer: A laboratory investigation

This paper presents a laboratory experiment to investigate how social motivations and free-form communication (Rich Communication) can facilitate coordinated resistance against divide-and-conquer transgressions. In our experiment, a leader first decides whether to extract surplus from a victim and shares it with a beneficiary. We find that the successful joint resistance rate increases almost four-fold (from 15 to 58%) when moving from more restrictive communication treatments to Rich Communication. We also find that the significant impacts of Rich Communication are driven more by the responders' ability to send free-form messages rather than the multiple and iterative opportunities to indicate intentions.     

Classification of natural language messages using a coordination game

The role of natural language communication in economic exchange has been the focus of substantial experimental analysis. Recently, scholars have taken the important step of investigating whether certain types of communication (e.g., promises) might affect decisions differently than other types of communication. This requires classifying natural language messages. Unfortunately, no broadly-accepted method is available for this purpose. We here describe a coordination game for classification of natural language messages. The game is similar in spirit to the “ESP” game that has proven successful for the classification of tens of millions of internet images. We compare our approach to self-classification as well as to classifications based on a standard content analysis. We argue that our classification game has advantages over those alternative approaches, and that these advantages might stem from the salient rewards earned by our game’s participants.     

Voice matters in a dictator game

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.

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Credible communication and cooperation: Experimental evidence from multi-stage Games

It is well known that communication often serves as a facilitator for cooperation in static games. Yet, communication can serve entirely different purposes in dynamic settings as communication during the game may work as a means for renegotiation, potentially undermining the credibility of cooperative strategies. To explore this issue, this paper experimentally investigates cooperation and non-binding communication in a two-stage game. More specifically, two treatments are considered: one with only pre-play communication and one where subjects can also communicate intra-play between the stages of the game. The results highlight a nontrivial difference concerning the effects of pre-play communication between the two treatments. Sending or receiving pre-play messages has a positive and significant effect on cooperation if there is no possibility of intra-play communication. However, this effect is significantly reduced when when intra-play communication is allowed. The results suggest that the credibility of pre-play messages may depend crucially on future communication opportunities.     

Dissertation abstract: A status theory of collective action

The “collective action problem” describes situations where each person in a group can individually profit more by withholding contributions to group goals. However, if all act in their material self-interest no public good is produced and all are worse off. I present a new solution to the collective action problem based on status. I argue that contributions to collective action increase an individual’s status in the group because contributions create perceptions of high group motivation, defined as the relative value an individual places on group versus individual welfare. Individuals are predicted to receive a variety of social and material benefits for their contributions to the group. These rewards can help explain why individuals contribute to collective action. Four laboratory studies tested the theory. In Study 1, following interaction in a 6-person public goods game, participants reported viewing higher contributors as more group motivated and higher status. Higher contributors also wielded more interpersonal influence in task interactions with participants. Participants also cooperated with higher contributors more, and allocated greater altruism to them in a Dictator game. Study 2 addressed an exchange-theoretic alternative explanation for the findings of Study 1, showing that observers of collective action who did not benefit from higher contributors’ contributions to the public good, nonetheless rated them as higher status, cooperated with them more, and gave them greater altruistic gifts. These results show that collective action contributors can earn social and material benefits even outside the group. Study 3 more directly tested the mediating role of group motivation. Contributors who sacrificed a greater proportion of resources for the collective action were rated as more group motivated and higher status than a moderate proportional contributor, even though the amounts they contributed were the same. These findings support the theory, and underscore the significance of self-sacrifice in the acquisition of status in collective action. Study 4 investigated the effects of status rewards on contributors’ behavior towards and perceptions of the group. Participants who received positive status feedback for their contributions subsequently contributed more than those who did not. Rewarded participants also identified more with the group and saw it as having greater solidarity and cohesion. I conclude by discussing theoretical implications and future research. JEL Classification C71     

Behavior in one-shot traveler’s dilemma games: model and experiments with advice

We report results of one-shot traveler’s dilemma game experiments to test the predictions of a model of introspection. The model describes a noisy out-of-equilibrium process by which players reach a decision of what to do in one-shot games. To test the robustness of the model and to compare it to other models of introspection without noise, we introduce non-binding advice. Advice has the effect of coordinating all players’ beliefs onto a common strategy. Experimentally, advice is implemented by asking subjects who participated in a repeated traveler’s dilemma game to recommend an action to subjects playing one-shot games with identical parameters. In contrast to observations, models based on best-response dynamics would predict lower claims than the advised. We show that our model’s predictions with and without advice are consistent with the data.      

An examination of the effect of messages on cooperation under double-blind and single-blind payoff procedures

Previous research has suggested that communication and especially promises increase cooperation in laboratory experiments. This has been taken as evidence for internal motivations such as guilt aversion or preference for promise keeping. The goal of this paper was to examine messages under a double-blind payoff procedure to test the alternative explanation that promise keeping is due to external influence and reputational concerns. Employing a 2×2 design, we find no evidence that communication increases the overall level of cooperation in our experiments with double-blind payoff procedures. However, we also find no evidence that communication impacts cooperation in our experiments with single-blind payoff procedures. Further, the payoff procedure does not appear to impact aggregate cooperation.     

Inter-gender interaction and communication in ultimatum games

In this article, we focus on bargaining within male–female pairs, the most pervasive partnership in humankind. We analyse data from an ultimatum game played by Greek participants. Parallel to this, we introduce a one-way communication protocol according to which the responders can send short messages to the receivers, after making their decisions. The analysis shows that gender and message effects exist and males are more effective bargainers.     

Synergy Goes to War: A Bioeconomic Theory of Collective Violence

Synopsis Synergy – here defined as otherwise unattainable combined effects that are produced by two or more elements, parts or individuals – has played a key causal role in the evolution of complexity, from the very origins of life to the evolution of humankind and complex societies. This theory – known as the ‘Synergism Hypothesis’ – also applies to social behavior, including the use of collective violence for various purposes: predation, defense against predators, the acquisition of needed resources and the defense of these resources against other groups and species. Among other things, there have been (1) synergies of scale, (2) cost and risk sharing, (3) a division of labor (or, better said, a ‘combination of labor’), (4) functional complementarities, (5) information sharing and collective ‘intelligence’, and (6) tool and technology ‘symbioses’. Many examples can be seen in the natural world – from predatory bacteria like Myxococcus xanthus to social insects like the predatory army ants and the colonial raiders Messor pergandei, mobbing birds like the common raven, cooperative pack-hunting mammals like wolves, wild dogs, hyenas and lions, coalitions of mate-seeking and mate-guarding male dolphins, the well-armed troops of savanna baboons, and, closest to humans, the group-hunting, group-raiding and even ‘warring’ communities of chimpanzees. Equally significant, there is reason to believe that various forms of collective violence were of vital importance to our own ancestors’ transition, over several million years, from an arboreal, frugivorous, mostly quadrupedal ape to a world-traveling, omnivorous, large-brained, tool-dependent, loquacious biped. The thesis that warfare is not a recent ‘historical’ invention will be briefly reviewed in this paper. This does not mean that humans are, after all, ‘killer apes’ with a reflexive blood-lust or an aggressive ‘drive’. The biological, psychological and cultural underpinnings of collective violence are far more subtle and complex. Most important, the incidence of collective violence – in nature and human societies alike – is greatly influenced by synergies of various kinds, which shape the ‘bioeconomic’ benefits, costs and risks. Synergy is a necessary (but not sufficient) causal agency. Though there are notable exceptions (and some significant qualifiers), collective violence is, by and large, an evolved, synergy-driven instrumentality in humankind, not a mindless instinct or a reproductive strategy run amok.      

Competition and coordination in experimental minority games

This work presents experimental results on a coordination game in which agents must repeatedly choose between two sides, and a positive fixed payoff is assigned only to agents who pick the minoritarian side. We conduct laboratory experiments in which stationary groups of five players play the game for 100 periods, and manipulate two treatment variables: the amount of information about other players’ past choices and the salience of information regarding the game history (i.e., the length of the string of past outcomes that players can see on the screen while choosing). Our main findings can be summarized as follows: aggregate efficiency in the game is in most cases significantly higher than the level corresponding to the symmetric mixed strategy Nash equilibrium. In addition, providing players with information about individual choices in the group does not improve aggregate efficiency with respect to when such information is absent. Displaying information about more rounds than just the previous one, on the other hand, seems to have a positive effect on aggregate efficiency. At the individual level, we find a stronger statistical relation between players’ current choices and their own past choices than between players’ choices and previous aggregate outcomes. In addition, the depth of the relation between present and past choices seems to be affected by the prompt availability of information about the game history. Finally, we detect evidence of a mutual co-adaptation between players’ choices over time that is partly responsible for the high level of efficiency observed.      

Abuse of EU Emissions Trading for Tacit Collusion

In this paper, we show that loopholes in EU emissions trading law foster tacit collusion that impacts oligopolistic product markets. The abuses originate from the covert misuse of EU emissions trading institutions, such as pooling or project-based mechanisms. We analyse two types of these loopholes by means of game theoretical methods to show how oligopolistic firms establish output restrictions, even if those firms are price takers on the~permit market (which might actually be the case for the majority of obligated firms in the EU). The identified misuse of emissions trading law increases firms’ profits, decreases the consumers’ surplus and has negative effects on social welfare for specified parameter ranges. Consequently, public authorities should not allow emissions trading’s overall good reputation—based upon its efficient abatement of pollution—to blind them to options in European emissions trading legislation that would eventually restrict competition.      

Communication, Risk, and Efficiency in Games

This paper uses curb sets to study the evolution of effective pre-play communication in games where a single communication round precedes a simultaneous-move, complete-information game. It is shown that the effectiveness of one-sided pre-play communication is inversely related to risk in the underlying game, and to the size of the message space. If messages have somea prioriinformation content, then multi-sided communication is more effective than one-sided communication; i.e., risk and the size of the message space play no role.Journal of Economic LiteratureClassification Number: C72.     

Policy uncertainty,symbiosis, and the optimal fiscal and monetary conservativeness

This paper extends a well-known macroeconomic stabilization game between monetary and fiscal authorities developed by Dixit and Lambertini (American Economic Review 93: 1522–1542) to multiplicative (policy) uncertainty. We find that even if fiscal and monetary authorities share a common output and inflation target (i.e., the symbiosis assumption), the achievement of the common targets is no longer guaranteed; under multiplicative uncertainty, in fact, a time consistency problem arises unless policymakers’ output target is equal to the natural level.     

An experimental analysis of cooperation and productivity in the trust game

In the standard trust game the surplus is increased by the risk taking first mover while cooperation by the second mover is a one-to-one transfer. This paper reports results from experiments in which the reverse holds; the first mover’s risky trust is not productive and the second mover’s cooperation is productive. This subtle difference significantly lowers the likelihood of trust but increases the likelihood of cooperation conditional on trust. Evidence is presented that the change in trust is consistent with first movers failing to anticipate the later result. Drawing upon the analogy that the trust game represents a model of exchange, the results suggest that markets should be organized so that the buyer moves first and not the seller as in the original trust game.

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Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.      

Environmental versus Human-Induced Scarcity in the Commons: Do They Trigger the Same Response?

We study appropriation strategies in common pool resources where extinction is a credible threat. Here we present an experimental study of the appropriation of common pool resources in a dynamic setting where resource availability depends on the initial environmental characteristics of the common resource and on human-induced resource depletion due to users’ appropriation patterns. Our results show that initial resource scarcity limits appropriation by inducing an initial caution among users that persists throughout of the game. Additionally, we find that subjects restrain their appropriation strategies when scarcity increases. However, this concern for resource scarcity is not enough to prevent resource depletion. Agents do not counteract the previous rounds’ appropriation strategies but follow the appropriation trend. High appropriation levels are followed by higher appropriation strategies, thus promoting the well known tragedy of the commons. Often concern for resource preservation is not great enough to limit appropriation.      

Individual autonomy in evolutionary game theory: defending Sugden against Ross’s accusation of eliminativism

In this paper, I provide a defence of Robert Sugden’s contribution to evolutionary game theory against Donald Ross’s accusation of eliminating the individual’s autonomy by denying the explanatory role of rationality, utility maximization and rational beliefs. In this regard, I claim that Sugden’s methodological remarks on evolutionary game theory do not imply a characterization of real agents as automata. On the methodological level, Sugden claims that it is not correct to conceive the empirical phenomenon of social evolution in terms of normative concepts, whose empirical status is not obvious. However, Sugden proposes a theory that explains the agent’s behaviour in terms of inductive reasoning, adaptive beliefs, salience and pattern recognition. The latter are psychological features that describe the way agents manage to self-determine their own actions. From these clarifications, I draw the conclusion that Ross’s critique misunderstands Sugden’s contribution both on the methodological and empirical level.     

Dissertation abstract: Voting in the laboratory

Almost every week national elections are held somewhere in the world. Many more elections take place at federal and local levels of government. Surely, these are important events to many of us. This thesis aims at providing a better understanding of why and how people vote in elections. Three original modifications of Palfrey and Rosenthal’s (1983) participation game are used to study voter turnout theoretically and experimentally.¹ In the basic game, each voter supports (i.e., prefers) one of two exogenous candidates and privately decides between voting at a cost and abstaining (without costs). The candidate who receives more votes wins the election (ties are broken randomly) and each supporter of this candidate receives an equal reward, independent of whether or not she voted. The first study (published in the American Political Science Review 100, pp. 235–248) analyzes the effects of social embeddedness on turnout, assuming that voters may be influenced by observing the decisions of other voters around them (e.g., a family or working place). Our experimental results show that the social context matters: this information increases turnout by more than 50%. The increase is greater when neighbors support the same candidate rather than when they support opponents. The second study investigates the effects of public opinion polls on voter turnout and welfare. Poll releases resolve uncertainty about the level of support for each candidate caused by `floating’ voters, whose preferences change across elections. This information increases turnout in the laboratory by 28–34%, depending on the fraction of floating voters in the electorate. If polls indicate equal levels of support for both candidates—in which case aggregate benefits for society are not affected by the outcome—welfare decreases substantially due to costs from excessive turnout. In the final study, elections are preceded by the competition between two candidates: they simultaneously announce binding policy offers in which some voters can be favored at the expense of others through inclusion and exclusion in budget expenditure (Myerson 1993).² We observe that policy offers include 33% more voters—yielding a smaller budget share for each—when voting is compulsory rather than voluntary. Moreover, we find evidence of political bonds between voters and long-lived parties. Overall, in all three experiments many subjects strongly react to economic incentives (i.e., benefits, costs, and informational clues), often in line with what is observed outside of the laboratory. JEL Classification C72, C92, D72 Dissertation Committee: Arthur Schram, University of Amsterdam (advisor) Axel Ockenfels, University of Cologne Thomas Palfrey, California Institute of Technology Cees van der Eijk, University of Nottingham Frans van Winden, University of Amsterdam ¹Palfrey, T.R., & Rosenthal, H. (1983). A strategic calculus of voting. Public Choice, 41, 7–53. ²Myerson, R.B. (1993). Incentives to cultivate favored minorities under alternative electoral systems. American Political Science Review, 87, 856–869.     

Recommended play and correlated equilibria: an experimental study

This study reports a laboratory experiment wherein subjects play a hawk–dove game. We try to implement a correlated equilibrium with payoffs outside the convex hull of Nash equilibrium payoffs by privately recommending play. We find that subjects are reluctant to follow certain recommendations. We are able to implement this correlated equilibrium, however, when subjects play against robots that always follow recommendations, including in a control treatment in which human subjects receive the robot “earnings.” This indicates that the lack of mutual knowledge of conjectures, rather than social preferences, explains subjects’ failure to play the suggested correlated equilibrium when facing other human players. We are grateful for financial support provided by the Purdue University Faculty Scholar program and the Asociación Méxicana de Cultura, as well as for the valuable research assistance provided by Shakun Datta and Marikah Mancini. We received helpful comments from Shurojit Chatterji, David Cooper, Arthur Schram, Ricard Torres, an anonymous referee, and from conference and seminar participants at Royal Holloway, the University of Amsterdam, Purdue University, the Economic Science Association and the Society for the Advancement of Economic Theory.