Logics for Social Behaviour


Time: 09:00 - 10:30am
Room: Murray 114 (Room 114, Murray Hall)
Campus map: Here

Day Speaker Title
Mon 11 July Rohit Parikh Knowledge, Games and the World
Tue 12 July Larry Moss Modal Logic Basics: technical background on logic for our workshop
Wed 13 July    Eric Pacuit Introduction to Epistemic Game Theory   
Thu 14 July Helle Hvid Hansen Modal Logics of Strategic Interaction
Fri 15 July Viktor Winschel Reflexive Economics and Higher Order Games



Speaker: Rohit Parikh, City University New York [Wikipedia] [Academia.edu]
Title: Knowledge, Games and the World [Slides]
Reasoning about knowledge and reasoning using knowledge occur at both the formal and informal levels. At the formal level we have the beautiful logical systems based on Kripke structures, or alternatively Aumann structures. But informal reasoning also occurs when using knowledge to choose one’s best action, or to theorize about the knowledge of others and to choose the best possible response to their likely actions. This creates a marriage of game theory and epistemic reasoning. If we stay at this informal level and keep our feet on the ground, then we see examples of the use of knowledge everywhere, in literature, in daily life, in politics, and even in the behavior of animals. Shakespeare makes much use of epistemic situations as do Bernard Shaw and Conan Doyle. But epistemic (or doxastic) reasoning can also be used to understand the behavior of tigers, of Siamese fish, or political candidates. Epistemic reasoning has played for a long time in its beautiful mathematical garden. But it also has much to offer the world in terms of understanding human, social, and animal behavior. We will give examples and offer a flexible theoretical framework.

Speaker: Larry Moss, Indiana University [Homepage]
Title: Modal Logic Basics: technical background on logic for our workshop [Slides] [Worksheet]
My session comes after Rohit Parikh's largely non-technical talk and before the three more challenging sessions to come. I will be providing background in dynamic epistemic logic and other topics that should enable newcomers to enter the subject. For the most part I present semantic models (and so I neglect proof theory). I will try to be very concrete at times. The point is to understand the models, to see the uses of formal models as well as the serious problems which motivates researchers to do better and better.

Speaker: Eric Pacuit, University of Maryland [Homepage]
Title: Introduction to Epistemic Game Theory [Slides]
Epistemic game theory aims at formalizing assumptions about knowledge, belief and rationality, and then studies their behavioral implications in games. In this talk, I will introduce epistemic game theory with a focus on representations of beliefs in games and how to use these representations to examine the assumptions that are built into any game-theoretic analysis of social interaction. Specifically, I will discuss the epistemic issues that arise when studying solution concepts, such as iterated removal of weakly dominated strategies, backward induction and forward induction. Time permitting, I will also introduce models of strategic reasoning in games and show how they can offer a new perspective on epistemic game theory. On this view, the rational outcomes of a game situation are arrived at through a process in which each decision maker settles on an optimal choice given her evolving beliefs about her own choice and her opponent's choices. The general conclusion is that the rational outcomes in a game situation depend not only on the structure of the game (i.e., the feasible actions and preferences for each player), but also on the participants' initial beliefs and inclinations, which update mechanisms are being used to update their beliefs and inclinations, and what exactly is commonly believed about the process of deliberation.

Speaker: Helle Hvid Hansen [Homepage]
Title: Modal Logics of Strategic Interaction [Slides]
Modal logics are simple yet expressive languages that have been used to formalise notions such as possibility/necessity, obligation/permission, knowledge and belief. In this talk, we will look at modal logics in which the modalities express what players can achieve in strategic games. The focus will be on Parikh's Game Logic and Pauly's Coalition Logic. In these logics, a modal formula \Box\phi states that an agent (or a coalition of agents) has a strategy to ensure an outcome that satisfies \phi. Since strategies may be mutually incompatible, these logics are non-normal, that is, the axiom \Box p \land \Box q -> \Box(p \land q) is not valid. Consequently, Kripke semantics is no longer adequate, instead these logics are interpreted over neighbourhood models. I will present basic theory and examples, survey existing results, discuss open questions, and if time permits, sketch the connection with recent work on coalgebraic dynamic logic.

Speaker: Viktor Winschel [Homepage]
Title: Reflexive Economics and Higher Order Games
A growing number of economists and computer scientists come to see commonalities in the foundations of computer science and economics. Notably reflexivity and compositionality that are at the foundations of computer science are also important features of models of social systems. I will present some important topics in economics that are approachable by the mathematical tools developed in computer science. I will also talk about our current work where we have adapted research from computer science in the field of game theory. Especially, I will show the ideas behind higher-order games and if time permits, string diagrams as a visual programming language for higher-order games.