Different solution concepts for strategic form games have been introduced in order to weaken the consistency assumption that players' beliefs - about their opponents strategic choices - are correct in equilibrium. The literature has shown that ambiguous beliefs are an appropriate device to deal...

In previous papers we studied a game model in which players' uncertainty is expressed entirely in the space of probabilities (lotteries) over consequences, it depends on the entire strategy profile chosen by the agents and it is described by the so called ambiguous beliefs correspondences. In...

The performance to a collective task may require a certain degree of cooperation among agents. Is cooperation viable in the sense that individual needs are fulfilled, compromises are possible and the task is performed? A model of cooperation is presented in which compromises are also ruled by...

Previous literature shows that, in many different models, limits of equilibria of perturbed games are equilibria of the unperturbed game when the sequence of perturbed games converges to the unperturbed one in an appropriate sense. The question whether such limit property extends to the...

In this paper we consider a model of games of incomplete information under ambiguity in which players are endowed with variational preferences. We provide an existence result for the corresponding mixed equilibrium notion. Then we study the limit behavior of equilibria under perturbations on the...

In this paper, we look at the (Kajii and Ui) mixed equilibrium notion, which has been recognized by previous literature as a natural solution concept for incomplete information games in which players have multiple priors on the space of payoff relevant states. We investigate the problem of...

We introduce a refinement concept for Nash equilibria (slightly altruistic equilibrium) defined by a limit process and which captures the idea of reciprocal altruism as presented in Binmore (2003). Existence is guaranteed for every finite game and for a large class of games with a continuum of...

This paper studies new refinement concepts for correlated equilibria based on altruistic behavior of the players and which generalize some refinement concepts introduced by the authors in previous papers for Nash equilibria. Effectiveness of the concepts, relations with the corresponding notions...

This paper studies how incentives are affected by intention-based reciprocity preferences when the principal hires many agents. Our results describe the agents' psychological attitudes required to sustain a given strategy profile. We also show that hiring reciprocal agents to implement a first...

In this paper, we look at the classical problem of aggregating individual utilities and study social orderings which are based on the concept of Ordered Weighted Averaging (OWA) Aggregating Operator. In these social orderings, called OWA social welfare functions (swf), weights are assigned a...