Modelling of Dynamic Games with Imperfect Information

Práce se zabývá studiem sekvenčních strategických her a to převážně her s nedokonalou informací, návrhem strategické situace vykazující prvky nedokonalé informace, implementací modelu a experimentováním s modelem. Pro práci byla zvolena hra DarkElf. Jedná se o tahovou strategickou ekonomicko-vojenskou hru, v níž se výsledné akce hráčů aplikují současně v předem známý okamžik.This work concentrates on the study of dynamic games; in particular games with imperfect information, implementation of a model and experimentation with the model. The game DarkElf was chosen for this project. It is a strategic, turn based game with economic and military features, where the decisions made by players are simultaneously implemented at a predetermined time.

Payoff-Based Dynamics for Multiplayer Weakly Acyclic Games

We consider repeated multiplayer games in which players repeatedly and simultaneously choose strategies from a finite set of available strategies according to some strategy adjustment process. We focus on the specific class of weakly acyclic games, which is particularly relevant for multiagent cooperative control problems. A strategy adjustment process determines how players select their strategies at any stage as a function of the information gathered over previous stages. Of particular interest are “payoff-based” processes in which, at any stage, players know only their own actions and (noise corrupted) payoffs from previous stages. In particular, players do not know the actions taken by other players and do not know the structural form of payoff functions. We introduce three different payoff-based processes for increasingly general scenarios and prove that, after a sufficiently large number of stages, player actions constitute a Nash equilibrium at any stage with arbitrarily high probability. We also show how to modify player utility functions through tolls and incentives in so-called congestion games, a special class of weakly acyclic games, to guarantee that a centralized objective can be realized as a Nash equilibrium. We illustrate the methods with a simulation of distributed routing over a network

Breakdowns

We study a continuous-time game of strategic experimentation in which the players try to assess the failure rate of some new equipment or technology. Breakdowns occur at the jump times of a Poisson process whose unknown intensity is either high or low. In marked contrast to existing models, we find that the cooperative value function does not exhibit smooth pasting at the efficient cut-off belief. This finding extends to the boundaries between continuation and stopping regions in Markov perfect equilibria. We characterize the unique symmetric equilibrium, construct a class of asymmetric equilibria, and elucidate the impact of bad versus good Poisson news on equilibrium outcomes

Using the markstrat business simulation to develop strategic management behaviours

It is well understood that experiential learning provides an incentive and impetus for accelerated learning, especially in humanities and business-focussed studies. ICT-based synthetic and virtual environments can provide a rich and varied context within which to achieve this. Specifically, this paper attempts to provide empirical, survey-based analysis of the application of a business simulation game, MarkStrat, on undergraduate and postgraduate programmes in this vein. The paper subsequently posits the pedagogic benefit of using such business simulation games for the development of strategic management behaviours across student sample populations and derives subsequent results to highlight associated learning behaviours

Negatively Correlated Bandits

We analyze a two-player game of strategic experimentation with two-armed bandits. Each player has to decide in continuous time whether to use a safe arm with a known payoff or a risky arm whose likelihood of delivering payoffs is initially unknown. The quality of the risky arms is perfectly negatively correlated between players. In marked contrast to the case where both risky arms are of the same type, we find that learning will be complete in any Markov perfect equilibrium if the stakes exceed a certain threshold, and that all equilibria are in cutoff strategies. For low stakes, the equilibrium is unique, symmetric, and coincides with the planner's solution. For high stakes, the equilibrium is unique, symmetric, and tantamount to myopic behavior. For intermediate stakes, there is a continuum of equilibria

Strategic Experimentation with Private Payoffs

We consider two players facing identical discrete-time bandit problems with a safe and a risky arm. In any period, the risky arm yields either a success or a failure, and the first success reveals the risky arm to dominate the safe one. When payoffs are public information, the ensuing free-rider problem is so severe that the equilibrium number of experiments is at most one plus the number of experiments that a single agent would perform. When payoffs are private information and players can communicate via cheap talk, the socially optimal symmetric experimentation profile can be supported as a perfect Bayesian equilibrium for sufficiently optimistic prior beliefs. These results generalize to more than two players whenever the success probability per period is not too high. In particular, this is the case when successes occur at the jump times of a Poisson process and the period length is sufficiently small

Disruptions in large value payment systems: an experimental approach

This experimental study investigates the behaviour of banks in a large value payment system. More specifically,we look at 1) the reactions of banks to disruptions in the payment system, 2) the way in which the history of disruptions affects the behaviour of banks (path dependency) and 3) the effect of more concentration in the payment system (heterogeneous market versus a homogeneous market). The game used in this experiment is a stylized version of a model of Bech and Garrett (2006) in which each bank can choose between paying in the morning (efficient) or in the afternoon (inefficient). The results show that there is significant path dependency in terms of disruption history. Also the chance of disruption influences the behaviour of the participants. Once the system is moving towards the inefficient equilibrium, it does not easily move back to the efficient one. Furthermore, there is a clear leadership effect in the heterogeneous market

"We are always after that balance":managing innovation in the new digital media industry

The pressure to innovate is growing as technology cycles change more rapidly. Organisations need to balance exploration and exploitation effectively if they are to heed the innovation imperative. Organisational ambidexterity is proposed as a means to achieve such balance with structural or contextual ambidexterity as possible choices. Yet how organisations become ambidextrous is an as yet underresearched area, and different industry sectors may pose different innovation challenges. Using the case study method, this paper examines how a computer games company responds to an industry-specific innovation challenge and how it endeavours to balance exploration and exploitation. The findings suggest that ambidexterity is difficult to achieve, and is fraught with organisational tensions which might eventually jeopardise the innovation potential of a company. The paper suggests that more qualitative research is needed to further our understanding of innovation challenges, innovation management and organisational ambidexterity