A One-Stage Model of Link Formation and Payoff Division

In this paper we introduce a strategic form model in which cooperation structures and divisions of the payoffs are determined simultaneously. We analyze the cooperation structures and payoff divisions that result according to Nash equilibria, strong Nash equilibria, and coalition proof Nash equilibria. We find that no cycle will be formed if a player claims a positive amount for the formation of one of its links and that a player does not necessarily profit from a central position in a cooperation structure. Journal of Economic Literature Classification Numbers: C71, C72.     

What does “clean” really mean? The implicit framing of decontextualized experiments

It is standard in experimental economics to use decontextualized designs where payoff structures are presented using neutral language. Here we show that cooperation in such a neutrally framed Prisoner’s Dilemma is equivalent to a PD framed as contributing to a cooperative endeavour. Conversely, there is substantially less cooperation in a PD framed as a competition. We conclude that in a decontextualized context, our participants by default project a cooperative frame onto the payoff structure.     

The limits of self-governance when cooperators get punished: Experimental evidence from urban and rural Russia

We report evidence from public goods experiments with and without punishment which we conducted in Russia with 566 urban and rural participants of young and mature age cohorts. Russia is interesting for studying voluntary cooperation because of its long history of collectivism, and a huge urban–rural gap. In contrast to previous experiments we find no cooperation-enhancing effect of punishment. An important reason is that there is punishment of contributors in all four subject pools. Thus, punishment can also undermine the scope for self-governance in the sense of high levels of voluntary cooperation that are sustained by sanctioning free riders only.     

Coordination and the Provision of Discrete Public Goods by Correlated Equilibria

The strategic analysis of the private provision of a discrete public good has shown the existence of multiple Nash equilibria with the efficient number of players voluntarily contributing. However the coordination issue is left unexplained by this literature. The experimental evidence shows that communication among players is helpful in achieving cooperation. We claim that, from the theoretical point of view, this is equivalent to playing correlated equilibria in an extended public good game with communication, modeled as Chicken. We characterize such equilibria as feasible coordination mechanisms to achieve public goods provision in the general contribution game. We further introduce a second kind of game characterized by payoff externalities that may persist after the minimal threshold of contributors is achieved. While it is easy to show the existence of Pareto efficient correlated equilibria in the first game, in the second one players face incentive problems such that a first best cannot always be an equilibrium. Nevertheless there exist correlated equilibria that can qualify as incentive efficient mechanisms, once free riding is seen as a moral hazard issue. Finally, with an example, we discuss the impact of coalition formation in our framework.     

Conditional cooperation in a sequential move game

Cooperation is a pervasive social phenomenon, but more often than not economic theories have little to say about its causes and consequences. In this paper, we explore the hypothesis that cooperative behaviour might be motivated by pure self-interest when the “social” payoff in a game is increasing. We report the results of a series of experiments on the Centipede game. The experiments are organised in two subsequent steps. Subjects first participate in a 2-period trust game, randomly matched with unknown partners. We apply the strategy method in order to elicit their social preferences. On the basis of their pre-game behaviour, individuals are divided into three main social groups: selfish individuals, pure altruists and reciprocators. At the second step of the experiment, subjects play a repeated 6-move Centipede game with an increasing final payoff. Each subject plays twice, in a low and in a high-stake Centipede game, and he/she is informed about his/her co-player social preferences. We provide statistical evidence to identify the origin of cooperation within homogeneous and heterogeneous social groups. We construct a Poisson regression model to assess the determinants of the duration of conditional cooperation in the Centipede.     

Not just like starting over - Leadership and revivification of cooperation in groups

We conduct a laboratory experiment to study how, after a history of decay, cooperation in a repeated voluntary contribution game can be revived in an enduring way. Simply starting the repeated game over—a simple fresh start—leads to an initial increase of cooperation, but to a subsequent new decay. Motivated by cooperation decay in organizations we study the potential of three interventions of triggering higher and sustained cooperation, which take place at the same time as a restart. Surprisingly, we find that the detailed explanation of the causes of the decay in cooperation of Fischbacher and Gächter (Am Econ Rev 100:541–556, 2010) combined with an advice on how to prevent decay do not have an effect beyond that of just starting over. In contrast, a one-way free form communication message sent by the leader to the followers strongly revives cooperation. We find evidence that repeated free form communication by the leader further strengthens the reviving effect on cooperation. Combining the two previous interventions does not outperform the pure effect of communication. Our content analysis reveals that leader communication is more people oriented than the expert advice.     

Demand Revelation,Hypothetical Bias,and Threshold Public Goods Provision

We examine the issues of hypothetical bias, demand revelation, and gender differences in a threshold public goods experiment with heterogeneous induced-values. First, we find no evidence of hypothetical bias in our threshold provision public goods experiments, despite the fact this is an open-ended type mechanism. Our results support recent experimental findings that use induced-values to investigate hypothetical bias. Second, we investigate the demand revealing performance of real and hypothetical payments and find no evidence that real payment performs better than hypothetical payment in our experiments. Third, we examine whether payments, real and hypothetical, are positively related to induced-values. Our results suggest there is statistical evidence that payments are positively related to true values. Finally, we examine the effect of gender on real and hypothetical payments in our experiment. The results show that gender matters for contributions through both real and hypothetical payments, after controlling for true values as well as socio-economic variables. Results also indicate that females are more likely to truthfully reveal their value than males through hypothetical payments, but gender is not significant for truthfully revealing their value through real payments.     

Experiment-inspired comments on John Roemer’s theory of cooperation

Abstract

We report on a nonsocial experiment where we find that all participants choose the dominant strategy in the experimental payoff, and compare it with the payoff-isomorphic, but social, Prisoner’s Dilemma treatment presented in a recent paper by Bosch-Domènech and Silvestre where 28% choose cooperation instead of the dominant strategy. The contrast reinforces Roemer’s emphasis on human cooperation. Next, we argue that Roemer’s Simple Kantian Equilibrium works well as a theory of cooperation under the assumption of monotonicity (positive or negative externalities), but not when efficient cooperation requires the division of labor by coordinating dissimilar tasks.     

The rise of cooperation in correlated matching prisoners dilemma: An experiment

Recently, there has been a Renaissance for multi-level selection models to explain the persistence of unselfish behavior in social dilemmas, in which assortative/correlated matching plays an important role. In the current study of a multi-round prisoners’ dilemma experiment, we introduce two correlated matching procedures that match subjects with similar action histories together. We discover significant treatment effects, compared to the control procedure of random matching. Particularly with the weighted history matching procedure we find bifurcations regarding group outcomes. Some groups converge to the all-defection equilibrium even more pronouncedly than the control groups do, while other groups generate much higher rate of cooperation, which is also associated with higher relative reward for a typical cooperative action. All in all, the data show that cooperation does have a much better chance to persist in a correlated/assortative-matching environment, as predicted in the literature. Electronic Supplementary Material Supplementary material is available in the online version of this article at . JEL Classification B52, C91, D74     

Heterogeneous quantal response equilibrium and cognitive hierarchies

We explore an equilibrium model of games where behavior is given by logit response functions, but payoff responsiveness and beliefs about others' responsiveness are heterogeneous. We study two substantively different ways of extending quantal response equilibrium (QRE) to this setting: (1) Heterogeneus QRE, where players share identical correct beliefs about the distribution of payoff responsiveness; and (2) Truncated QRE, where players have downward looking beliefs, systematically underestimating others' responsiveness. We show that the cognitive hierarchy model is a special case of Truncated QRE. We conduct experiments designed to differentiate these approaches. We find significant evidence of payoff responsive stochastic choice, and of heterogeneity and downward looking beliefs in some games.     

The effects of heterogeneous interaction and risk attitude adaptation on the evolution of cooperation

This paper addresses the evolution of cooperation in a multi-agent system with agents interacting heterogeneously with each other based on the iterated prisoner’s dilemma (IPD) game. The heterogeneity of interaction is defined in two models. First, agents in a network are restricted to interacting with only their neighbors (local interaction). Second, agents are allowed to adopt different IPD strategies against different opponents (discriminative interaction). These two heterogeneous interaction scenarios are different to the classical evolutionary game, in which each agent interacts with every other agent in the population by adopting the same strategy against all opponents. Moreover, agents adapt their risk attitudes while engaging in interactions. Agents with payoffs above (or below) their aspirations will become more risk averse (or risk seeking) in subsequent interactions, wherein risk is defined as the standard deviation of one-move payoffs in the IPD game. In simulation experiments with agents using only own historical payoffs as aspirations (historical comparison), we find that the whole population can achieve a high level of cooperation via the risk attitude adaptation mechanism, in the cases of either local or discriminative interaction models. Meanwhile, when agents use the population’s average payoff as aspirations (social comparison) for adapting risk attitudes, the high level of cooperation can only be sustained in a portion of the population (i.e., partial cooperation). This finding also holds true in both of the heterogeneous scenarios. Considering that payoffs cannot be precisely estimated in a realistic IPD game, simulation experiments are also conducted with a Gaussian disturbance added to the game payoffs. The results reveal that partial cooperation in the population under social comparison is more robust to the variation in payoffs than the global cooperation under historical comparison.     

An experimental study of prosocial motivation among criminals

The fact that criminal behavior typically has negative consequences for others provides a compelling reason to think that criminals lack prosocial motivation. This paper reports the results from two dictator game experiments designed to study the prosocial motivation of criminals. In a lab experiment involving prisoners, we find a striking similarity in the prosocial behavior of criminals and non-criminals, both when they interact with criminals and when they interact with non-criminals. Similarly, in an Internet experiment on a large sample from the general population, we find no difference in the prosocial behavior of individuals with and without a criminal record. We argue that our findings provide evidence of criminals being as prosocially motivated as non-criminals in an important type of distributive situations.     

Should you pay off your mortgage or invest?

The mortgage payoff dilemma affects many retirees that have enough financial assets to pay off their mortgage. I find that, on average, retirees with less than $300,000 in non-housing financial wealth are better off keeping the mortgage and investing.     

Facebook-to-Facebook: online communication and economic cooperation

Direct face-to-face communication has traditionally been found to be more effective for fostering economic cooperation than any form of indirect, mediated communication. We inquire whether this is still the case since most young adults routinely use texting and online social media to communicate with each other. We find that young adults in our laboratory public goods experiment are just as adept at finding and sustaining cooperative agreements when communicating within a Facebook group and through online chat as they are in person.     

When less information is good enough: experiments with global stag hunt games

There is mixed evidence on whether subjects coordinate on the efficient equilibrium in experimental stag hunt games under complete information. A design that generates an anomalously high level of coordination, Rankin et al. (Games Econo Behav 32(2):315–337, 2000), varies payoffs each period in repeated play rather than holding them constant. These payoff “perturbations” are eerily similar to those used to motivate the theory of global games, except the theory operates under incomplete information. Interestingly, that equilibrium selection concept is known to coincide with risk dominance, rather than payoff dominance. Thus, in theory, a small change in experimental design should produce a different equilibrium outcome. We examine this prediction in two treatments. In one, we use public signals to match Rankin et al. (2000)’s design; in the other, we use private signals to match the canonical example of global games theory. We find little difference between treatments, in both cases, subject play approaches payoff dominance. Our literature review reveals this result may have more to do with the idiosyncrasies of our complete information framework than the superiority of payoff dominance as an equilibrium selection principle.     

When Overlapping Organisations Play Two-Level Games: IMF–EU Interaction in Credit Lending to Latvia and Greece

In the literature, the cooperation of the IMF and the EU in credit lending has been discussed either from a state-centric, bureaucratic or institutionalist perspective. In this article, we examine the Troika as a set-up of multiple organisational overlap providing bureaucratic agents with constraints and opportunities for strategic action. Taking Latvia and Greece as cases in point, we analyse who prevails in a situation of conflict and why. How do these international organisations manage to overcome their differences and reach consensus? Drawing on the Two-Level game approach, we argue that negotiators are more likely to prevail over each other when their respective win-set decreases. We find that different strategies to manipulate win-sets are decisive to explain both cooperation and assertiveness. Changing costs of no agreement during a lending programme as well as the institutional procedures for programme ratification facilitate the use of these strategies.     

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.     

Discrimination via Exclusion: An Experiment on Group Identity and Club Goods

We study using laboratory experiments the impact on cooperation of allowing individuals to invest in group‐specific, excludable public goods. We find that allowing different social groups to voluntarily contribute to such goods increases total contributions. However, a significant proportion of that contribution goes toward the group‐specific club good rather than the public good, even when the latter has higher financial returns to cooperation. We find significant evidence of in‐group biases, which are manifested by positive in‐group reciprocity. That is, club goods allow subjects to display their preferences for interaction with their in‐group members, as well as positive in‐group reciprocity.     

There are many evolutionary pathways to cooperation

Current sociobiological discussions attribute the evolution of cooperation to only two main influences: kinship and reciprocity. As a baseline, the paper analyzes the extent of incidental cooperation achieved in three important 2 × 2 payoff environments (Prisoners' Dilemma, Chicken, and Tender Trap) and the two simplest 'rules of the game' or protocols of play (single-round simultaneous-move and single-round sequential move). Kinship promotes cooperation beyond these base levels by modifying payoffs of selfish versus unselfish behaviors. Reciprocity may also promote cooperation, but its expression requires protocols that widen available strategy sets (in comparison with the basic strategies in the underlying 2 × 2 payoff matrices). Once payoff modifications and/or more elaborate protocols are allowed, many other pathways to cooperation are opened up. Among them are punishment options, complementary strategy mixes, recognition effects, coordination using external clues, and group selection.     

Optimal guessing: Choice in complex environments

In this paper, we extend the analysis of our earlier work on boundedly rational learning in an i.i.d. setting [Easley and Rustichini, Econometrica 67 (1999) 1157-1184] to complex decision problems. We show that the axioms from our earlier analysis can be applied in this more complex setting, and along with some new axioms, they asymptotically yield expected utility maximization. Perhaps most important is our demonstration of a simple procedure that insures expected payoff maximization no matter what Markov process the underlying process on states follows. We view this result as providing a positive learning result for all worlds in which learning is possible.