Equilibrium Vengeance

The efficiency-enhancing role of the vengeance motive is illustrated in a simple social dilemma game in extensive form. Incorporating behavioral noise and observational noise in random interactions in large groups leads to seven continuous families of (short run) Perfect Bayesian equilibria (PBE) that involve both vengeful and non-vengeful types. A new long run evolutionary equilibrium concept, Evolutionary Perfect Bayesian Equilibrium (EPBE), shrinks the equilibrium set to two points. In one EPBE, only the non-vengeful type survives and there are no mutual gains. In the other EPBE, both types survive and reap mutual gains.reciprocity; vengeance; evolutionary perfect Bayesian equilibrium; social dilemmas

Equilibrium Vengeance

This paper introduces two ideas, emotional state dependent utility components (ESDUCs), and evolutionary perfect Bayesian equilibrium (EPBE). Using a simple extensive form game, we illustrate the efficiency-enhancing role of a powerful ESDUC, the vengeance motive. Incorporating behavioral noise and observational noise leads to a range of (short run) Perfect Bayesian equilibria (PBE) involving both vengeful and non-vengeful types. We then derive two (long run) EPBE, one where both types survive and reap mutual gains, and a second where only the non-vengeful type survives and there are no mutual gains.negative reciprocity, perfect Bayesian equilibrium, evolutionary perfect Bayesian equilibrium, emotional state dependent utility

Equilibrium Vengeance

The efficiency-enhancing role of the vengeance motive is illustrated in a simple social dilemma game in extensive form. Incorporating behavioral noise and observational noise in random interactions in large groups leads to seven continuous families of (short run) Perfect Bayesian equilibria (PBE) that involve both vengeful and non-vengeful types. A new long run evolutionary equilibrium concept, Evolutionary Perfect Bayesian Equilibrium (EPBE), shrinks the equilibrium set to two points. In one EPBE, only the non-vengeful type survives and there are no mutual gains. In the other EPBE, both types survive and reap mutual gains

Vengefulness Evolves in Small Groups

We discuss how small group interactions overcome evolutionary problems that might otherwise erode vengefulness as a preference trait. The basic viability problem is that the fitness benefits of vengeance often do not cover its personal cost. Even when a sufficiently high level of vengefulness brings increased fitness, at lower levels, vengefulness has a negative fitness gradient. This leads to the threshold problem: how can vengefulness become established in the first place? If it somehow becomes established at a high level, vengefulness creates an attractive niche for cheap imitators, those who look like highly vengeful types but do not bear the costs. This is the mimicry problem, and unchecked it could eliminate vengeful traits. We show how within-group social norms can solve these problems even when encounters with outsiders are also important.

When Victims Seek Closure: Forgiveness, Vengeance and the Role of Government

This article discusses the role of victims and their families in the sentencing of criminal defendants, including the emotional and ethical components of victims\u27 desires to achieve justice and closure

Behavioral economics as applied to firms: a primer

We discuss the literatures on behavioral economics, bounded rationality and experimental economics as they apply to firm behavior in markets. Topics discussed include the impact of imitative and satisficing behavior by firms, outcomes when managers care about their position relative to peers, the benefits of employing managers whose objective diverges from profit-maximization (including managers who are overconfident or base pricing decisions on sunk costs), the impact of social preferences on the ability to collude, and the incentive for profit-maximizing firms to mimic irrational behavior.Behavioral economics, bounded rationality, experimental economics, oligopoly, antitrust

Homo Æqualis: A Cross-Society Experimental Analysis of Three Bargaining Games

Data from three bargaining games-the Dictator Game, the Ultimatum Game, and the Third-Party Punishment Game-played in 15 societies are presented. The societies range from US undergraduates to Amazonian, Arctic, and African hunter-gatherers. Behaviour within the games varies markedly across societies. The paper investigates whether this behavioural diversity can be explained solely by variations in inequality aversion. Combining a single parameter utility function with the notion of subgame perfection generates a number of testable predictions. While most of these are supported, there are some telling divergences between theory and data: uncertainty and preferences relating to acts of vengeance may have influenced play in the Ultimatum and Third-Party Punishment Games; and a few subjects used the games as an opportunity to engage in costly signalling.

Behavioral Economics as Applied to Firms: A Primer

We discuss the literatures on behavioral economics, bounded rationality and experimental economics as they apply to firm behaviour in markets. Topics discussed include the impact of imitative and satisficing behavior by firms, outcomes when managers care about their position relative to peers, the benefits of employing managers whose objective diverges from profit-maximization (including managers who are overconfident or base pricing decisions on sunk costs), the impact of social preferences on the ability to collude, and the incentive for profit-maximizing firms to mimic irrational behavior.behavioral economics, firms, oligopoly, bounded rationality, collusion

Homo Æqualis: A Cross-Society Experimental Analysis of Three Bargaining Games

Data from three bargaining games-the Dictator Game, the Ultimatum Game, and the Third-Party Punishment Game-played in 15 societies are presented. The societies range from USundergraduates to Amazonian, Arctic, and African hunter-gatherers. Behaviour within the games varies markedly across societies. The paper investigates whether this behavioural diversity can be explained solely by variations in inequality aversion. Combining a single parameter utility function with the notion of subgame perfection generates a number of testable predictions. While most of these are supported, there are some telling divergences between theory and data: uncertainty and preferences relating to acts of vengeance may have influenced play in the Ultimatum and Third- Party Punishment Games; and a few subjects used the games as an opportunity to engage in costly signalling.Bargaining Games, cross-cultural experiments, inequality aversion