On Tuesday, April 10, at 3 p.m., Sunil Simon (CWI) will give a talk at the LIRa seminar. The topic is Choosing products in social networks.
The talk will take place in Science Park 904, Room A1.04.
We study using game-theoretic concepts, the consequences of adopting products by agents who form a social network. We use the threshold model of social networks in which the nodes influenced by their neighbours can adopt one out of several alternatives, and associate with each social network a strategic game between the agents. Like certain classes of potential games, these games exhibit the “join the crowd” property where the payoff of each player weakly increases if more players choose the same strategy. However, such games may have no Nash equilibrium and determining the existence of a Nash equilibrium is NP-complete. The situation changes when the underlying graph of the social network is a DAG, a simple cycle, or has no source nodes. For these three classes we characterize Nash equilibria and determine the complexity of existence of a Nash equilibrium.