Keynote Speakers

Abstract: We are all familiar with mathematical algorithms, like the Euclidean algorithm for finding the GCD of two natural numbers. Or the more complex algorithm to find out if a given number is prime. But there are algorithms in society all over the place. An election is an algorithm for finding the will of the people, an important issue until Kenneth Arrrow showed in 1950 that the project could not succeed. There is a more successful algorithm Vickrey auction which allows people to bid their true value for an object without fear that they might be bidding too much or too little. But the theory of social algorithms (or social software as it was once called) has not been studied enough. It does occur in Economics as the theory of Mechanism Design, or in computer science as Distributed Computation.

One important project then is to study social algorithms as a field unto themselves, discover their properties and find out what is possible, what is easy, what is difficult and what is impossible. A related area is Epistemic Logic. Even when agents, as with Adam Smith, are motivated by self interest they can evaluate their interest, and hence their best move, only in terms of what they know or believe. This field has been well studied since the mid 1980’s and the TARK conferences, held biennially, have been devoted to it. And yet there is insufficient study of how knowledge influences behavior, both individual and social. Two plays of Shakespeare, Hamlet and Othello are both concerned with knowledge. Hamlet because of doubt, or lack of knowledge. Othello because of a false belief which causes him to murder Desdemona. This phenomenon causes us to think of false beliefs created globally by various sources, the mass media, or the social media. How in these difficult times can we extract reliable information from the many sources available to us? And how can we protect ourselves from bad actions caused by false beliefs?

Selected references:

•  Arrow, Kenneth J. (1950). “A Difficulty in the Concept of Social Welfare”. Journal of Political Economy, 58 (4): 328–346.

•  Farrell, Joseph, and Matthew Rabin. “Cheap talk.” Journal of Economic perspectives, 10.3 (1996): 103-118.

• Parikh, Rohit. “Social software.” Synthese 132 (2002): 187-211.

• Parikh, Rohit, C ̧ a ̆gil Ta ̧sdemir, and Andreas Witzel. “The power of knowledge in games.” International Game Theory Review, 15.04 (2013): 1340030.

• Stalnaker, Robert. “Saying and meaning, cheap talk and credibility.” Game theory and pragmatics. London: Palgrave Macmillan UK, 2006. 83-100.

• Vickrey, William. “Counterspeculation, auctions, and competitive sealed tenders.” The Journal of finance, 16.1 (1961): 8-37.

Abstract: In games on graphs, we generally consider two or more players playing a turn-based game by moving a token through a directed graph, tracing out a finite or infinite path. Such simple games provide us with compelling tools for reasoning about diverse phenomena arising in areas like computer science, logic, linguistics, economics, mathematics, philosophy, and biology. One usually considers different variants of such graph games where the variations  arise from different winning conditions (e.g., reachability, parity), independent moves of players (e.g., cop and robber game), one player obstructing moves of the others (e.g., sabotage game, poison game) and similar others.

In this talk, we would study frameworks describing reasoning in these games starting from the simple  travel games, and moving on to certain  variants like cops and robber game and sabotage game. We would analyse actions and strategies of the players and also the information available to them with respect to their positions and moves. Our primary focus for this talk would be the cops and robber game, alongside we would briefly touch upon the other ones as well.