201,296 research outputs found

    Plausible Cooperation, Second Version

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    There is a large repeated games literature illustrating how future interactions provide incentives for cooperation. Much of this literature assumes public monitoring: players always observe precisely the same thing. Even slight deviations from public monitoring to private monitoring that incorporate differences in players’ observations dramatically complicate coordination. Equilibria with private monitoring often seem unrealistically complex. We set out a model in which players accomplish cooperation in an intuitively plausible fashion. Players process information via a mental system — a set of psychological states and a transition function between states depending on observations. Players restrict attention to a relatively small set of simple strategies, and consequently, might learn which perform well.Repeated games, private monitoring, bounded rationality, cooperation

    Random Topologies and the emergence of cooperation: the role of short-cuts

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    We study in detail the role of short-cuts in promoting the emergence of cooperation in a network of agents playing the Prisoner's Dilemma Game (PDG). We introduce a model whose topology interpolates between the one-dimensional euclidean lattice (a ring) and the complete graph by changing the value of one parameter (the probability p to add a link between two nodes not already connected in the euclidean configuration). We show that there is a region of values of p in which cooperation is largely enhanced, whilst for smaller values of p only a few cooperators are present in the final state, and for p \rightarrow 1- cooperation is totally suppressed. We present analytical arguments that provide a very plausible interpretation of the simulation results, thus unveiling the mechanism by which short-cuts contribute to promote (or suppress) cooperation

    Spillover modes in multiplex games: double-edged effects on cooperation, and their coevolution

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    In recent years, there has been growing interest in studying games on multiplex networks that account for interactions across linked social contexts. However, little is known about how potential cross-context interference, or spillover, of individual behavioural strategy impact overall cooperation. We consider three plausible spillover modes, quantifying and comparing their effects on the evolution of cooperation. In our model, social interactions take place on two network layers: one represents repeated interactions with close neighbours in a lattice, the other represents one-shot interactions with random individuals across the same population. Spillover can occur during the social learning process with accidental cross-layer strategy transfer, or during social interactions with errors in implementation due to contextual interference. Our analytical results, using extended pair approximation, are in good agreement with extensive simulations. We find double-edged effects of spillover on cooperation: increasing the intensity of spillover can promote cooperation provided cooperation is favoured in one layer, but too much spillover is detrimental. We also discover a bistability phenomenon of cooperation: spillover hinders or promotes cooperation depending on initial frequencies of cooperation in each layer. Furthermore, comparing strategy combinations that emerge in each spillover mode provides a good indication of their co-evolutionary dynamics with cooperation. Our results make testable predictions that inspire future research, and sheds light on human cooperation across social domains and their interference with one another

    The absent-minded prisoner

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    If one of two rational players is absent-minded for at least three rounds, cooperation in a prisoners dilemma with a finite number of repetitions is possible. If both players are absentminded, even two rounds of absent-mindedness can be enough for cooperation in these rounds and all rounds before. Sufficient conditions for the existence of a cooperative equilibrium are derived, a plausible interpretation of absent-mindedness in the case of many repetitions is given. --absent-mindedness,prisoners dilemma,repeated games

    Effecting Cooperation

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    There is a large repeated games literature illustrating how future interactions provide incentives for cooperation. Much of this literature assumes public monitoring: players always observe precisely the same thing. Even slight deviations from public monitoring to private monitoring that incorporate differences in players’ observations dramatically complicate coordination. Equilibria with private monitoring often seem unrealistically complex. We set out a model in which players accomplish cooperation in an intuitively plausible fashion. Players process information via a mental system — a set of psychological states and a transition function between states depending on observations. Players restrict attention to a relatively small set of simple strategies, and consequently, might learn which perform well.Repeated games, private monitoring, bounded rationality, cooperation

    Core Allocations for Cooperation Problems in Vaccination

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    Vaccination is a very effective measure to fight an outbreak of an infectious disease, but it often suffers from delayed deliveries and limited stockpiles. To use these limited doses of vaccine effectively, health agencies can decide to cooperate and share their doses. In this study, we analyze this type of cooperation. Typically cooperation leads to an increased total return, but cooperation is only plausible when this total return can be distributed in a stable way. This makes cooperation a delicate matter. Using cooperative game theory, we derive theoretical sufficient conditions under which cooperation is plausible (i.e., the core is non-empty) and we show that the doses of vaccine can be traded for a market price in those cases. We perform numerical analyses to generalize these findings and we derive analytical expressions for market prices that can be used in general for distributing the total return. Our results demonstrate that cooperation is most likely to be plausible in case of severe shortages and in case of sufficient supply, with possible mismatches between supply and demand. In those cases, trading doses of vaccine for a market price often results in a core allocation of the total return. We confirm these findings with a case study on the redistribution of influenza vaccines

    Prisoners' Other Dilemma

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    We find that contrary to common perception, cooperation as equilibrium of the infinitely repeated discounted prisoner's dilemma is in many relevant cases not very plausible, or at least questionable: for a significant subset of the payoff-discount factor parameter space cooperation equilibria are strictly risk dominated by non-cooperation (according to the Harsanyi-Selten 1988 criterion). Examples include collusion equilibria in the repeated Cournot duopoly.Prisoner's Dilemma; Risk dominance; Repeated games; Equilibrium selection; Cooperation; Collusion;

    Normative Conflict & Feuds: The Limits of Self-Enforcement

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    A normative conflict arises when there exist multiple plausible norms of behavior. In such cases, norm enforcement can lead to a sequence of mutual retaliatory sanctions, which we refer to as a feud. We investigate the hypothesis that normative conflict enhances the likelihood of a feud in a public-good experiment. We find that punishment is much more likely to trigger counter-punishment and start a feud when there is a normative conflict, than in a setting in which no conflict exists. While the possibility of a feud sustains cooperation,the cost of feuding fully offsets the efficiency gains from increased cooperation.normative conflict; peer punishment; feuds; counter-punishment; social norms

    Coordinating Aid for Regional Cooperation Projects: The Experience of Central Asia

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    For the Central Asian countries the dissolution of the Soviet Union led to economic disintegration as old coordination mechanisms disappeared and new national borders appeared. This paper analyses why it has been difficult to coordinate aid for regional cooperation projects (e.g., on the Aral Sea or trade facilitation) whose economic benefits appear positive. Bilateral aid flows to Central Asia have been dominated by geopolitical rather than economic considerations, and have been at best narrowly national in focus and at worst regionally divisive. Regional organizations composed of Central Asian countries and various neighbours have also competed rather than cooperated, so that the most plausible source of coordinated aid for regional cooperation projects is the multilateral agencies. A key role for aid donors is to provide technical assistance in analysing and explaining benefits, and how these affect various interests. Initial advantages which multilateral agencies had as impartial providers of technical advice were undermined in 1992-93 when the IMF?s strong position in favour of retaining the ruble turned out to be...aid, Central Asia, trade

    Coordinating Aid for Regional Cooperation Projects: The Experience of Central Asia

    Get PDF
    For the Central Asian countries the dissolution of the Soviet Union led to economic disintegration as old coordination mechanisms disappeared and new national borders appeared. This paper analyses why it has been difficult to coordinate aid for regional cooperation projects (eg. on the Aral Sea or trade facilitation) whose economic benefits appear positive. Bilateral aid flows to Central Asia have been dominated by geopolitical rather than economic considerations, and have been at best narrowly national in focus and at worst regionally divisive. Regional organizations composed of Central Asian countries and various neighbours have also competed rather than cooperated, so that the most plausible source of coordinated aid for regional cooperation projects is the multilateral agencies. A key role for aid donors is to provide technical assistance in analysing and explaining benefits, and how these affect various interests. Initial advantages which multilateral agencies had as impartial providers of technical advice were undermined in 1992-3 when the IMF’s strong position in favour of retaining the ruble turned out to be mistaken advice. In the 1990s aid directed to the Aral Sea problem produced few benefits because, despite the magnitude of the gross benefits from reversing the desiccation, littoral countries see differential benefits and costs; pure win-win situations are more likely from regional cooperation in trade facilitation. Subsequently the multilateral agencies have had a better focus, sharing priorities in the destination of aid and agreeing on a functional division of labour, but this has not yet translated into effective assistance for regional cooperation.
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