Commitment: a game-theoretical and logical perspective

Many social interactions between agents demand the use of commit-ments to reach socially efficient or avoid socially inefficient outcomes. Commitments express the desires, goals, or intentions of the agents in an interaction. In this article, we distinguish between unilateral and bi-lateral commitments, and between whether or not an agent has to agree with a commitment made by the other agent before the commitment becomes effective. Using a game-theoretic model, we will show that, depending on the incentive structure, different interactions require dif-ferent types of commitments to reach socially efficient outcomes. Based on these results, we discuss whether existing (or slightly adapted) logi-cal formalizations are adequate for the description of certain types of commitments and which formalization is suitable for reaching a so-cially efficient outcome in a specific interaction. We claim that a logical formalization of commitment aiming at a socially efficient outcome should be based on assumptions about the type of interaction and the suitable type of commitment. A more general conclusion of this article is that game-theoretic arguments can help to provide specifications for logical formalizations of systems of more agents if one has an idea about the incentive structure of the interaction.