Network Creation Games: Think Global - Act Local

We investigate a non-cooperative game-theoretic model for the formation of communi-cation networks by selfish agents. Each agent aims for a central position at minimumcost for creating edges. In particular, the general model (Fabrikant et al., PODC’03)became popular for studying the structure of the Internet or social networks. De-spite its significance, locality in this game was first studied only recently (Bilò et al.,SPAA’14), where a worst case locality model was presented, which came with a highefficiency loss in terms of quality of equilibria. Our main contribution is a new andmore optimistic view on locality: agents are limited in their knowledge and actionsto their local view ranges, but can probe different strategies and finally choose thebest. We study the influence of our locality notion on the hardness of computing bestresponses, convergence to equilibria, and quality of equilibria. Moreover, we comparethe strength of local versus non-local strategy-changes. Our results address the gapbetween the original model and the worst case locality variant. On the bright side,our efficiency results are in line with observations from the original model, yet wehave a non-constant lower bound on the price of anarchy.