Game Theoretic Study of Networks

Abstract. In this thesis we study the efficiency of systems, in which, users share resources. We assume that the users are selfish and we use principles of Game Theory for our study. In the first part of the thesis, we theoretically study the influence of the systems efficiency due to selfish-ness. The basic tool that we use in our study is the Price of Anarchy [32, 44]. In the second part of the thesis, we study algorithms (mechanisms), in order to remedy the situation due to selfishness. A Mechanism is an algorithm that aims at leading the players into actions desirable for the system and achieve this goal by appropriately modifying the parameters of the game.