The evolution of strategy in bacterial warfare via the regulation of bacteriocins and antibiotics

Bacteria inhibit and kill one another with a diverse array of compounds, including bacteriocins and antibiotics. These attacks are highly regulated, but we lack a clear understanding of the evolutionary logic underlying this regulation. Here, we combine a detailed dynamic model of bacterial competition with evolutionary game theory to study the rules of bacterial warfare. We model a large range of possible combat strategies based upon the molecular biology of bacterial regulatory networks. Our model predicts that regulated strategies, which use quorum sensing or stress responses to regulate toxin production, will readily evolve as they outcompete constitutive toxin production. Amongst regulated strategies, we show that a particularly successful strategy is to upregulate toxin production in response to an incoming competitor’s toxin, which can be achieved via stress responses that detect cell damage (competition sensing). Mirroring classical game theory, our work suggests a fundamental advantage to reciprocation. However, in contrast to classical results, we argue that reciprocation in bacteria serves not to promote peaceful outcomes but to enable efficient and effective attacks.

Sociological game theory: agency, social structures and interaction processes

This article presents two sociological theories, alternatives to classical game theory. These social science-based game theories discussed here present reformulations of classical game theory in applied mathematics (CGT). These theories offer an important advance to classical game theory, thanks to the application of central concepts in sociology and social psychology, as well as the results of empirical analyses of individual and collective behaviour. These two theories emerging in the social sciences are, the first, based on systems theory, is social science game theory (SGT); the other is Erwing Goffman’s interactionist theory (IGT) based on social psychology. Each of these theories, both focused on the analysis of social games, are presented and contrasted with classical game theory, highlighting the centrality of social rules in structuring and regulating human behaviour, and the need to include them in any analysis.

When team play matters: Building revenue management in tourism destinations

Competition between tourism destinations is intensifying, and collaboration between stakeholders can increase destination appeal. Until now, such collaboration has limited itself to governance and marketing. To advance an earlier proposal of destination revenue management (RM), we develop a conceptual framework of instigators and limiters to such cooperation between tourism operators. Next, we synthesize the framework with behavioral game theory (BGT), an extension of classical game theory that challenges the utility maximization-based outcomes of the classical version. BGT incorporates additional aspects, such as reciprocity and fairness, into bargaining and cooperation and supports the feasibility of forming a RM alliance. Based on BGT findings, our synthesis provides theoretical and practical insights into how destinations can improve their competitiveness through cooperation in two important RM areas, pricing and demand creation.

Quantum Conditional Strategies and Automata for Prisoners’ Dilemmata under the EWL Scheme

Classical game theory is an important field with a long tradition of useful results. Recently, the quantum versions of classical games, such as the prisoner’s dilemma (PD), have attracted a lot of attention. This game variant can be considered as a specific type of game where the player’s actions and strategies are formed using notions from quantum computation. Similarly, state machines, and specifically finite automata, have also been under constant and thorough study for plenty of reasons. The quantum analogues of these abstract machines, like the quantum finite automata, have been studied extensively. In this work, we examine well-known conditional strategies that have been studied within the framework of the classical repeated PD game. Then, we try to associate these strategies to proper quantum finite automata that receive them as inputs and recognize them with a probability of 1, achieving some interesting results. We also study the quantum version of PD under the Eisert–Wilkens–Lewenstein scheme, proposing a novel conditional strategy for the repeated version of this game.

Emergence and suppression of cooperation by action visibility in transparent games

Real-world agents, such as humans, animals and robots, observe each other during interactions and choose their own actions taking the partners’ ongoing behaviour into account. Yet, classical game theory assumes that players act either strictly sequentially or strictly simultaneously (without knowing the choices of each other). To account for action visibility and provide a more realistic model of interactions under time constraints, we introduce a new game-theoretic setting called transparent game, where each player has a certain probability to observe the choice of the partner before deciding on its own action. Using evolutionary simulations, we demonstrate that even a small probability of seeing the partner’s choice before one’s own decision substantially changes evolutionary successful strategies. Action visibility enhances cooperation in a Bach-or-Stravinsky game, but disrupts cooperation in a more competitive iterated Prisoner’s Dilemma. In both games, strategies based on the “Win–stay, lose–shift” and “Tit-for-tat” principles are predominant for moderate transparency, while for high transparency strategies of “Leader-Follower” type emerge. Our results have implications for studies of human and animal social behaviour, especially for the analysis of dyadic and group interactions.

Compatibility in tax reporting

Purpose – to describe a compliance-monitoring equilibrium in presence of compatibility costs in a setting when managers and other parties have different attitude towards compliance. Design/Method/Approach. Classical game theory – Nash equilibrium. Findings. If compatibility costs are small, there exist a unique stable Nash equilibrium of the game between the tax authority and a population of heterogeneous firms. In this equilibrium, the relation between compatibility costs and compliance is non-monotonic and depends on the curvature of auditing function. However, compatibility costs reduce non-compliance in low cheating regimes and may enhance it when many firms are cheating. Limitations. The model is at high level of abstraction and neglects many important detail that characterize each field where it could be potentially applied. Theoretical implications. The results provide one rationale for developing countries to be cautious with employing refined auditing schemes and for developed countries to promote complicated accounting procedures. Originality/value. Compatibility costs are not previously considered in economic analysis of compliance. Paper type – conceptual.