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We study from both a theoretical and an empirical perspective how a network of military alliances and enmities affects the intensity of a conflict. The model combines elements from network theory and from the politico-economic theory of conflict. We postulate a Tullock contest success function augmented by an externality: each group’s strength is increased by the fighting effort of its allies, and weakened by the fighting effort of its rivals. We obtain a closed form characterization of the Nash equilibrium of the fighting game, and of how the network structure affects individual and total fighting efforts. We then perform an empirical analysis using data on the Second Congo War, a conflict that involves many groups in a complex network of informal alliances and rivalries. We estimate the fighting externalities, and use these to infer the extent to which the conflict intensity can be reduced through (i) removing individual groups involved in the conflict; (ii) pacification policies aimed at alleviating animosity among groups.

We enrich the choice task of responders in ultimatum games by allow- ing them to independently decide whether to collect what is offered to them and whether to destroy what the proposer demanded. Such a multidimensional response format intends to cast further light on the motives guiding responder behavior. Using a conservative and strin- gent approach to type classification, we find that the overwhelming majority of responder participants choose consistently with outcome- based preference models. There are, however, few responders that destroy the proposer's demand of a large pie share and concurrently reject their own offer, thereby suggesting a strong concern for integrity.

Multiple prizes are usually awarded in contests (e.g., internal promotions, school admissions, sports, etc.) and players exert effort to increase their chances for winning a higher prize. A multi-prize contest model must provide each player's probabilities of winning each prize as functions of all players’ efforts. We find that the key notion of “hypothetical subcontests” in the contest axiomatization literature initiated by Skaperdas (1996) can be appropriately interpreted and precisely defined from a ranking perspective, as well as the relevant axioms of “ Subcontest Consistency ” and “ Independence of Irrelevant Contestants ” (IIC). When there are less than four contestants (exclusive), a set of axioms properly adapted from those in Skaperdas (1996) and Clark and Riis (1998a) are sufficient and necessary for axiomatizing the widely adopted multi-prize nested lottery contest of Clark and Riis (1996a) . When there are more than four contestants (inclusive), including a new axiom of “ Independence of Irrelevant Ranks ” (IIR) is necessary and sufficient.

We consider a multi-battle team contest in which players from two rival teams form pairwise matches to fight in distinct component battles, which are carried out sequentially or (partially) simultaneously. A team wins if and only if its players win a majority of battles. Each player benefits from his team's win, while he can also receive a private reward for winning his own battle. We find that the outcomes of past battles do not distort the outcomes of future battles. Neither the total expected effort nor the overall outcome of the contest depends on the contest's temporal structure or its feedback policy. (JEL C72, D72, D74, D82)

Conflict parties are frequently involved into more than one conflict at a given time. In this paper the interrelated structure of conflictive relations is modeled as a conflict network where opponents are embedded in a local structure of bilateral conflicts. Conflict parties invest in specific conflict technology to attack their respective rivals and defend their own resources. We show that there exists a unique equilibrium for this conflict game and examine the relation between aggregated equilibrium investment (interpreted as conflict intensity) and underlying network characteristics. The derived results have implications for peaceful resolutions of conflicts because neglecting the fact that opponents are embedded into an interrelated conflict structure might have adverse consequences for conflict intensity.

This paper is concerned with methods for analysing patterns of conflict. We survey dynamic games, differential games, and simulation as alternative ways of extending the standard static economic model of conflict to study patterns of conflict dynamics, giving examples for each type of model. It turns out that computational requirements and theoretical difficulties impose tight limits on what can be achieved using the first two approaches. In particular, we appear to be forced to model the outcome of conflict as being decided in a single final confrontation if we employ non-linear contest success functions. A simulation study based on a new model of adaptive, boundedly rational decision making, however, is shown not to be subject to this limitation. Plausible patterns of conflict dynamics emerge, which we can link to both historical conflict and standard tenets of military theory.

In intergroup contests a manager advises and motivates her group’s members. Her rewards often depend on the subsequent contest expenditure of the members. I test whether such incentives undermine the credibility and effectiveness of a manager’s efforts. In the different experimental treatments the managers either benefit from very high or low expenditure or get a predetermined payment. The results show that different management incentives shape the expenditure of the group members even if managers have an advisory role only. However, group members follow recommendations more closely if management compensation is not linked to contest expenditures.

This paper proposes a multi-prize “reverse” nested lottery contest model, which can be viewed as the “mirror image” of the conventional nested lottery contest of Clark and Riis (1996a) . The reverse-lottery contest model determines winners by selecting losers based on contestants’ one-shot effort through a hypothetical sequence of lotteries. We provide a microfoundation for the reverse-lottery contest from a perspective of (simultaneous) noisy performance ranking and establish that the model is underpinned by a unique performance evaluation rule. We further demonstrate that the noisy-ranking model can be interpreted intuitively as a “worst-shot” contest, in which contestants’ performances are evaluated based on their most severe mistakes. The reverse-lottery contest model thus depicts a great variety of widely observed competitive activities of this nature. A handy closed-form solution for a symmetric equilibrium of the reverse-lottery contest is obtained. We show that the winner-take-all principle continues to hold in reverse-lottery contests. Moreover, we find that a reverse-lottery contest elicits more effort than a conventional lottery contest whenever the prizes available to contestants are relatively scarce.

Vendettas occur in many real-world settings where rivals compete for a prize, e.g., winning a competitive promotion or retaining a job, by engaging in aggressive, retaliatory behavior. We present a benchmark experiment where two players have an initial probability of winning a prize. Retaliatory vendettas occur and lead subjects to the worst possible outcomes in 2/3 of cases, counter to self-interest predictions, with large inefficiencies even in the absence of any immediate gain from aggression. Negative emotions are important and interact with the economic setting to produce large social inefficiencies. Allowing cooling off periods reduces aggression. (JEL C72, D74)

Contest functions (alternatively, contest success functions) determine probabilities of winning and losing as a function of contestants’ e ort. They are used widely in many areas of economics that employ contest games, from tournaments and rent-seeking to conflict and sports. We first examine the theoretical foundations of contest functions and classify them into four types of derivation: stochastic, axiomatic, optimally-derived, and microfounded. The additive form (which includes the ratio or "Tullock" functional form) can be derived in all four di erent ways. We also explore issues in the econometric estimation of contest functions, including concerns with data, endogeneity, and model comparison.

When considering engaging in conflict to secure control of a resource, a group needs to predict the amount of post-conflict leakage due to infiltration by members of losing groups. We use this insight to explain why conflict often takes place along ethnic lines, why some ethnic groups are more often in conflict than others (and some never are), and why the same groups are sometimes in conflict and sometimes at peace. In our theory ethnic markers help enforce group membership: in homogeneous societies members of the losing group can more easily pass themselves as members of the winning group, and this reduces the chances of conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance between ethnic groups, group sizes, income inequality, and expropriable resources. One of the insights is that the incidence of ethnic conflict is nonmonotonic in expropriable resources as a fraction of total resources, with a low incidence for either low or high values. We use the model’s predictions to interpret historical examples of conflict associated with skin pigmentation, body size, language, and religion.

Envy is often the cause of mutually harmful outcomes. We experimentally study the impact of envy in a bargaining setting in which there is no conflict in material interests: a proposer, holding the role of residual claimant, chooses the size of the pie to be shared with a responder, whose share is exogenously fixed. Responders can accept or reject the proposal, with game types differing in the consequences of rejection: all four combinations of (not) self-harming and (not) other-harming are considered. We find that envy leads responders to reject high proposer claims, especially when rejection harms the proposer. Notwithstanding, maximal claims by proposers are predominant for all game types. This generates conflict and results in a considerable loss of efficiency.

Two wealth effects typically arise in any contest: i) wealth decreases the marginal cost of effort, but also ii) decreases the marginal benefit of winning the contest. In this paper, we introduce three types of strategic contest models depending on whether the first, second, or both wealth effects play a role: namely, a privilege contest, an ability contest, and a rent-seeking contest. Our theoretical analysis reveals that the effects of wealth and wealth inequality are strongly “contestdependent” and are complex in the sense that they depend on the decisiveness of the contest and on the higher-order derivatives of the utility functions of wealth. Our analysis thus does not support general claims that the rich should lobby more or that low economic growth and wealth inequality should lead to additional conflicts.

In imperfectly discriminating contests with symmetric valuations, equilibrium payoffs are positive shares of the value of the prize. In contrast to a bargaining situation, players’ shares sum to less than one because a residual share of the value is lost due to rent dissipation. In this paper, we consider contests with two players and investigate the relationship between these equilibrium shares and the parameters of a class of asymmetric Tullock contest success functions. Our main finding is that any players’ shares that sum up to less than one can arise as the unique outcome of a pure-strategy Nash equilibrium for appropriate parameters.

Hausken (2008a) formulates a contest-theoretic model of the attack and defense of a network of targets. This note identi es a technical error that invalidates Hausken's characterization of Nash equilibrium for a substantial portion of the parameter space that he examines and provides necessary conditions for his solution to form a pure- strategy Nash equilibrium. Many of the existing results in the contest-theoretic liter- ature on the attack and defense of networks of targets rely upon Hausken's (2008a) characterization and require corresponding parameter restrictions. When these restric- tions are not met, the analysis of Clark and Konrad (2007) and Kovenock and Roberson (2010a) provides a foundation for constructing mixed-strategy Nash equilibria.

We study the framing effects of communication on payoffs in multiparty bargaining. Communication has been shown to be more truthful and revealing than predicted in equilibrium. Because talk is preference-revealing, it may effectively frame bargaining around a logic of fairness or competition, moving parties on a path toward or away from equal-division agreements. These endogenous framing effects may outweigh any overall social utility effects due to the mere presence of communication. In two studies, we find that non-binding talk about fairness within a three-party, complete-information game leads toward off-equilibrium, equal division payoffs, while non-binding talk focusing on Competitive Reasoning moves parties away from equal divisions. Our two studies allow us to demonstrate that manipulated pre-game talk and spontaneous within-game dialogue lead to the same results.

We analyze the performance of various communication protocols in a generalization of the Crawford-Sobel (1982) model of cheap talk that allows for multiple receivers. We find that whenever the sender can communicate informatively with both receivers by sending private messages, she can communicate informatively by sending public messages. In particular, it is possible that informative communication with one or both receivers is impossible in private, but possible in public. When the sender is allowed to send both public and private messages, it is possible for the sender to combine the commitment provided by public communication with the flexibility provided by private communication and transmit more information to the receivers than under either private or public communication scenarios. When the players can communicate through a mediator and the receivers are biased in the same direction, it is optimal for the sender to communicate with the receivers through independent private noisy communication channels. It is in general optimal to take advantage of pooling the sender’s truthtelling constraints across the receivers when they are biased in the opposite directions.

Game-theoretic model of election to a corporate board of directors is proposed. It is shown that the equilibrium distribution of seats is unique. The uniqueness guarantees nonmanipulability of elections. The distribution is obtained by the d’Hondt method of seats distribution in proportional representation problem. The model is tested on real data from a Russian company.

We study how conflict in a contest game is influenced by rival parties being groups and by group members being able to punish each other. Our main motivation stems from the analysis of socio-political conflict. The relevant theoretical prediction in our setting is that conflict expenditures are independent of group size and independent of whether punishment is available or not. We find, first, that our results contradict the independence of groupsize prediction: conflict expenditures of groups are substantially larger than those of individuals, and both are substantially above equilibrium. Towards the end of the experiment material losses in groups are 257% of the predicted level. There is, however, substantial heterogeneity in the investment behaviour of individual group members. Second, allowing group members to punish each other after individual contributions to the contest effort are revealed leads to even larger conflict expenditures. Now material losses are 869% of the equilibrium level and there is much less heterogeneity in individual group members’ investments. These results contrast strongly with those from public goods experiments where punishment enhances efficiency and leads to higher material payoffs.

The same contestants often meet repeatedly in contests. Behavior in a contest potentially provides information with regard to one's type and can therefore influence the behavior of the opponents in later contests. This paper shows that if effort is observable, this can induce a ratchet effect in contests: high ability contestants sometimes put in little effort in an early round in order to make the opponents believe that they are of little ability. The effect reduces overall effort and increases equilibrium utility of the contestants when compared with two unrelated one-shot contests. It does, however, also introduce an allocative inefficiency since sometimes a contestant with a low valuation wins. The model assumes an imperfectly discriminating contest. In an extension I show that, qualitatively, results are similar in a perfectly discriminating contest (all pay auction).

We examine the effects of providing more accurate information to a political decision-maker who is lobbied by competing interests. Conventional wisdom holds that such a bias in the direction of the correct decision improves the efficiency of government. We provide a formal definition of bias which is derived from the same fundamentals that give rise to a contest model of lobbying. Efficiency of government is measured by both the probability of taking the correct decision and the amount of social waste associated to lobbying activities. We present a benchmark model in which increasing the bias always improves the efficiency of government under both criteria. However, this result is fragile in the sense that reasonable alternative assumptions in the micro-foundations lead to slightly different models in which -due to different strategic effects of bias- under either criterion there is no guarantee that more accurate information improves government.

This paper highlights the importance of natural resource concentration and ethnic group regional concentration for ethnic conflict. The existence of multiple conflict terrains (and hence multiple threat points) is the source of bargaining failure, similar to the one determined by the presence of offensive advantages. The theory predicts war to be more likely when resource concentration and group concentration are high, and the empirical analysis, both at the country level and at the ethnic group level, confirms the essential role of geographic concentration variables for civil war.

We analyze the determinants of tacit collusion in an infinitely repeated contest with noise in the contest success function. Sustaining collusion via Nash reversion strategies is easier the more noise there is, and is more difficult the larger is the contest's prize value. An increase in the contest's number of players can make sustaining collusion either more or less difficult.

Violence and coercion are key to understanding economic and social interactions in any society. This premise was used by North et al. (2009) to distinguish three `patterns of social organization' that societies have used to solve the problem of violence. We model one of these, the `limited access order', that is still dominant today. This order is characterized by an elite coalition that uses coercion to extract economic rents, while restricting violence and containing bandits. Since violence is key, we choose to apply insights from the economic literature on conflict and appropriation. Our model puts structure on the main elements of the limited access order. It allows us to assess some of its characteristics, by identifying conditions under which a sizeable elite emerges that is capable of limiting the activities of bandits and thereby provides order and stability. Our results show large variations in elite size, appropriation, production levels, and welfare across limited access societies due to only minor variations in exogenous model parameters, such as productivity, the cost of conflict, and the decisiveness of conflict. A striking result is that, within the limited access order, unproductive societies are faced with a high tax rate and a large elite, while productive societies are faced with a low tax rate and a small elite. The difference in additional productivity between these societies is offset by increased appropriation by bandits in absence of a strong elite, resulting in welfare being maximized for moderate levels of productivity.

In order to determine the optimal allocation of responsibilities in disease interventions, and in designing commitment mechanisms, the paper develops a three-period game comprising policy- makers, the international community providing financial aid, and individuals. A policy-maker chooses, in period 1, a fraction of funds to be allocated to disease prevention, and the remaining fraction is allocated to disease treatment. The policy-maker chooses additional funds provision in period 2 for disease treatment. The international community chooses funding in period 3 for disease treatment. Persons engage in risky versus safe behavior which may or may not cause disease contraction. When the international community funds, the policy-maker free rides by not funding additionally. We determine which factors impact how the policy-maker allocates funding between disease prevention and treatment. If the policy-maker funds substantially, the international community free rides by funding less. We quantify how more allocation of funds by the policy-maker to disease prevention causes lower disease contraction probability and higher probability that a person remains sick or dies, and how the international community’s funding impacts these two probabilities. We derive seven assertions from the properties of the model. The model is also tested against empirical data on Africa. The results show consistency between the theoretical model and empirical estimates.

While folk theorems for dynamic renewable common pool resource games sustain cooperation as an equilibrium, the possibility of reverting to violence to appropriate the resource destroys the incentives to cooperate, because of the expectation of conflict when resources are sufficiently depleted. In this paper, we provide experimental evidence that individuals behave according to the theoretical predictions. For high stocks of resources, when conflict is a highly costly activity, participants cooperate less than in the control group, and they play the non-cooperative action with higher frequency. This comes as a consequence of the (correct) anticipation that, when resources run low, the conflict option is used by a large share of participants.

Arguments are statements used to persuade someone or in support of a claim. However, these are not perfect and part are be exploited by the opponent to build its own argumentation. In this paper we present a litigation success function (LSF) that considers the quality of the plainti¤ and defendant arguments and preserves the flexibility and analytical characteristics of the "rent-seeking" contest success function. On the contrary to the existent literature, the proposed LSF can be applied to the English fee shifting system, and to model criminal and civil proceedings.

The present paper offers a methodological contribution on Schelling's insight into game theory drawing both on his proposition for a "reorientation of game theory" and his dynamic models of residential segregation. It aims to show how these respective works exhibit coherence in Schelling's thinking. It is often claimed that Schelling criticizes standard game theory without proposing any conceptual solution. To the contrary, I assert that the methodological constraints Schelling identifies in standard game theory support the proposition of a new type of modeling in the dynamic models of residential segregation: the first agent based modeling. I argue that the agent-based models provide a theoretic ground to formalize the methodological innovations proposed in his “reorientation of game theory.” To understand such a claim I stress the social ontology underlined in Schelling's conception of a "theory of interdependent decisions."

This paper studies a contest in which players with unobservable types may form an alliance in a pre-stage of the game to join their forces and compete for a prize. We characterize the pure strategy equilibria of this game of incomplete information. We show that if the formation of an alliance is voluntary, players do not reveal private information in the process of alliance formation in any equilibrium. In this case there exists a pooling equilibrium without alliances with a unique effort choice in the contest and there exist equilibria in which all types prefer to form an alliance. If the formation of an alliance can be enforced by one player with positive probability there exists an equilibrium in which only the low types prefer to form an alliance.

Consider a situation where players in a prisoner's dilemma game can approve or reject the other's choice such as cooperation or defection. If both players approve the other's choice, the outcome is the one they chose, whereas if either one rejects the other's choice, the outcome is the one when both defect, which we name the approval mechanism herein (this is inspired by the Cold War doctrine of mutually assured destruction). Experimentally, we find that the cooperation rate with the approval mechanism is 90% in round one and averages 93.2% across the 19 rounds. The questionnaire analysis also allows us to find that subjects' behavior is consistent with subgame perfect elimination of weakly dominated strategies (SPEWDS) rather than Nash equilibrium (NE) or subgame perfect Nash equilibrium (SPNE) behavior. Theoretically, this mechanism implements cooperation in SPEWDS, but not in NE or SPNE.

I examine the circumstances under which a sophisticated time-inconsistent decisionmaker (i) will not or (ii) need not severely miscoordinate her behavior across time, in the sense of following a course of action which fails to be Pareto-optimal for the sequence of temporal selves of the individual (Laibson [1994] and O'Donoghue and Rabin [1999] provide prominent instances of such miscoordination). Studying the standard solution concept for this case - Strotz-Pollak equilibrium - in general decision problems with perfect information, I establish two results: first, for finite-horizon problems without indifference, essential consistency (Hammond [1976]) is sufficient for choice to be Pareto-optimal. Second, if the decision problem satisfies a certain history-independence property, whenever an equilibrium outcome fails to be Pareto-optimal, it is Pareto-dominated by another equilibrium outcome, leading to an existence result for a Pareto-optimal solution.

We study interactions with different durations and termination rules in a (quasi) continuous-time prisoner’s dilemma experiment. We find that cooperation is easier to achieve and sustain with deterministic horizons than with stochastic ones; end-game effects emerge, but subjects postpone them with experience; longer duration helps cooperation. Static theories for continuous-time games cannot simultaneously account for these findings and miss the evolution of behavior across supergames. We propose a simple model – based on the replicator dynamics – that proves consistent with this evidence. The analysis of strategies and an additional treatment lend further support to the proposed explanation.

In this paper, we generalize the General Lotto game and the Colonel Blotto game to allow for battlefield valuations that are heterogeneous across battlefields and asymmetric across players, and for the players to have asymmetric resource constraints. We completely characterize Nash equilibrium in the generalized version of the General Lotto game and then show how this characterization can be applied to identify equilibria in the Colonel Blotto version of the game. In both games, we find that there exist sets of non-pathological parameter configurations of positive Lebesgue measure with multiple payoff nonequivalent equilibria.

The reverse nested lottery contest proposed by Fu et al. (2014) is the “mirror image” of the classical nested lottery contest of Clark and Riis (1996a), which has been axiomatized by Lu and Wang (2015). In this paper, we close the gap and provide an axiomatic underpinning for the reverse nested lottery contest by identifying a set of six necessary and sufficient axioms. These axioms proposed specify the properties of contestants’ probabilities of being ranked the lowest among all players or within subgroups, while the axiomatization of the classical nested lottery contest by Lu and Wang (2015) relies on axioms on contestants’ probabilities of being ranked the highest among all players or within subgroups.

Subjects in the loss domain tend to split payoffs equally when bargaining. The ultimatum game offers an ideal mechanism through which economists can investigate whether equal splits are the consequence of proposer generosity or due to their anticipation that the responders will reject lower offers. This paper experimentally compares ultimatum bargaining in a loss domain with that under gains. The results reveal that, although responders do not expect more in the loss domain, proposers do make higher offers. As such, proposers reach agreements more often in the loss domain than they do in the gains domain, and responders receive higher payoffs., Working paper series, ISSN 2628-1724, 2015, Heft 9

This paper develops a positive analysis of alliance formation that builds on a simple economic model featuring a “winner-take-all” contest for control of some resource. When an alliance forms, members pool their efforts in that contest and,if successful, apply the resource to a joint production process. The analysis does not assume that the alliance has some special advantage in the conflict or that the joint production process exhibits increasing returns. Nor is there any presumption that peace prevails among the alliance members. In this setting, the analysis finds that, due to the familiar free-rider problem, the formation of alliances tends to reduce the severity of the conflict over the contestable resource. Furthermore, despite the internal conflict that arises among the winning alliance’s members over the distribution of their joint product, under reasonable conditions this effect alone is sufficient to support stable alliance formation in a noncooperative equilibrium.

Altruists and envious people who meet in contests are symbionts. They do better than a population of narrowly rational individuals. If there are only altruists and envious individuals, a particular mixture of altruists and envious individuals is evolutionarily stable.

This paper develops a positive analysis of stable group formation, highlighting the role of conflict management within groups. The analysis is based on a model of sequential conflict, starting with a "winner- take-all" contest for control of some resource. When a group forms, members pool their efforts in that contest and, if successful, apply the resource to a joint production process. While reducing the severity of conflict over the contestable resource relative to the case of individual conflict, the formation of groups adds another layer of conflict---that is, one between the members of the winning group over the distribution of their joint product. The effectiveness of conflict management in enabling groups to resolve this second layer of conflict in more "peaceful" ways involving less "social waste" has some important implications for the equilibrium structure of groups as well as for the allocation of resources.

We study a bilateral multi-issue bargaining procedure with complete information and endogenous unrestricted agenda, in which offers can be made in any subset of outstanding issues. We find necessary and sufficient conditions for this procedure to have a unique subgame perfect equilibrium agreement.

Kovenock and Roberson's (2012a, b) replication of Hausken’s (2008a) equations and parameter restrictions do not enhance our insight into the defense and attack of reliability systems. This reply intends to fill the remaining understanding gaps.

I study a model of a long-term partnership with two-sided incomplete information. The partners jointly determine the stakes of their relationship and individually decide whether to cooperate with or betray each other over time. I characterize the extremal— interim incentive efficient —equilibria. In these equilibria, the partners generally “start small,” and the level of interaction grows over time. The types of players separate quickly. Further, cooperation between “good” types is viable regardless of how pessimistic the players are about each other initially. The quick nature of separation in an extremal equilibrium contrasts with the outcome selected by a strong renegotiation criterion (as studied in Watson (1999, J. Econ. Theory 85 , 52–90). Journal of Economic Literature Classification Numbers: C72, C73, D74.

We consider rules (strategies, commitments, contracts, or computer programs) that make behavior contingent on an opponent’s rule. The set of perfectly observable rules is not well defined. Previous contributions avoid this problem by restricting the rules deemed admissible. We instead limit the information available about rules. Each player can only observe which class, out of a collection of classes smaller than the number of rules, the opponent’s rule belongs to. For any underlying 2-player, finite, normal-form game there is a game extended with coarsely observable strategies that has equilibria with payoffs arbitrarily close to any feasible, individually rational payoff profile.

Given the substantial evidence of behavioral heterogeneity in social dilemma experiments, in this study we consider how to achieve cooperation in n-player prisoner's dilemma situations where each player has one behavioral type, either selfish or conditionally cooperative. We introduce a two-stage game form called the stay-leave mechanism, where each cooperator has the chance to revise his choice when players' choices are not unanimous. For homogeneous behavioral type cases, theory predicts that the unique outcome is cooperative under the stay-leave mechanism, regardless of the benefit derived from cooperation. For heterogeneous behavioral type cases, we show that the benefits of cooperation shrink such that the unique outcome is cooperative under the stay-leave mechanism if the number of conditionally cooperative players increases. The average cooperation rate in the stay-leave mechanism experiment is 86.6% across 15 periods, which increases to 96.0% after period 5. We also provide evidence that selfish and conditionally cooperative types coexist throughout the sessions, in the proportion that the equilibrium outcome is cooperative. Our results corroborate the importance of incorporating behavioral heterogeneity into institutional design.

This paper shows that second thoughts are not an innocent device in our daily life, but is human wisdom that plays an important role in resolving problems such as social dilemmas. We design a simple mechanism to achieve Pareto efficiency in social dilemmas, and then compare the performance of this mechanism with and without second thoughts. First, second thoughts change the payoff structure of the game in favor of cooperation. Second, this mechanism is robust even when players deviate from a payoff maximizing behavior.

We analyze a simple sequential algorithm (SA) for allocating indivisible items that are strictly ranked by n ≥ 2 players. It yields at least one Pareto-optimal allocation which, when n = 2, is envy-free unless no envy-free allocation exists. However, an SA allocation may not be maximin or Borda maximin—maximize the minimum rank, or the Borda score—of the items received by a player. Although SA is potentially vulnerable to manipulation, it would be difficult to manipulate in the absence of one player’s having complete information about the other players’ preferences. We discuss the applicability of SA, such as in assigning people to committees or allocating marital property in a divorce.

International audience; Mission-driven nonprofit organizations compete for donations through fundraising activities. Such competition can lead to inefficient outcomes, if nonprofits impose externalities on each others' output. This paper studies the sustainability of fundraising coordination agreements, using a game-theoretic model of coalition formation. We show that three key characteristics determine the stability of cooperation between nonprofits: (i) the alliance formation rule, (ii) the extent to which fundraising efforts are strategic complements/substitutes, and (iii) whether deviation from the agreements is by an individual or by a group of nonprofits. We analyze how the interaction of these three features induces (or not) the stability of Pareto-optimal full coordination in fundraising.

The standard theoretical description of rent-seeking contests is that of rational individuals or groups engaging in socially inefficient behavior by exerting costly effort. Experimental studies find that the actual efforts of participants are significantly higher than predicted in the models based on rational behavior and that over-dissipation of rents (or overbidding or over-expenditure of resources) can occur. Although over-dissipation cannot be explained by the standard rational-behavior theory, it can be explained by incorporating behavioral dimensions into the standard model, such as (1) the utility of winning, (2) relative payoff maximization, (3) bounded rationality, and (4) judgmental biases. These explanations are not exhaustive but provide a coherent picture of important behavioral dimensions to be considered when studying rent-seeking behavior in theory and in practice.

Wir illustrieren den Einsatz von Simulationstechniken zur Betrachtung komplexer Dynamiken in asymmetrischen Konfliktsituationen mit begrenzt rationalen Akteuren. Dazu wird erst ein formaler Modellrahmen entwickelt, dessen Steady state wir bestimmen. Darauf baut eine Umsetzung des Modells in SIMULINK und die Entwicklung von Entscheidungsverfahren für die Spieler auf. Anhand eines Basisszenarios diskutieren wir typische Verläufe von asymmetrischen Konflikten.

Standard theoretical prediction is that rational economic agents participating in rent-seeking contests should engage in socially inefficient behavior by exerting costly efforts. Experimental studies find that the actual efforts of participants are significantly higher than predicted and that over-dissipation of rents (or overbidding or over-expenditure of resources) can occur. Although the standard theory cannot explain over-dissipation, this phenomenon can be explained by incorporating behavioral dimensions into the rent-seeking contest, such as (1) the utility of winning, (2) relative payoff maximization, (3) bounded rationality, and (4) judgmental biases. These explanations are not exhaustive, but they provide a coherent picture of important behavioral dimensions that should be considered when studying rent-seeking behavior in theory and in practice.

Multiple prizes are usually awarded in contests (e.g., internal promotions, school admissions, sports, etc), and players exert effort to increase their chances for winning a higher prize. A multi-prize contest model must provide each player's probabilities of winning each prize as functions of all players.efforts. This paper generalizes the ax-iomatization framework of Skaperdas (1996) and Clark and Riis (1998a) by considering the probabilities of complete rankings of players for their given efforts. Necessary and sufficient axioms are identi.ed to axiomatize the widely adopted multi-prize nested lottery contest of Clark and Riis (1996a), as well as its mirror image, the "reverse"nested lottery contests recently proposed by Fu, Lu and Wang (2014). The axioms of Skaperdas (1996) and Clark and Riis (1998a) need to be appropriately reformulated (and thus reinterpreted) from the ranking perspective. The axiomatization requires one new axiom of .Independence from Irrelevant Ranks.(IIR) if and only if the contest in- volves (strictly) more than three players. Our axiomatization framework integrates the single-prize and multi-prize lottery contest models, it also uni.es the conventional and reverse nested lottery contests and further illustrates their .mirror image.relationship.