Competition for the access to and use of information in networks

In a network formation framework, where payoffs reflect an agent's ability to access information from direct and indirect contacts, we integrate negative externalities due to connectivity associated with two types of effects: competition for the access to information, and rivalrous use of information. We consider two separate models to capture the first and the second situations, respectively. In the first model, we assume that information is a non-rivalrous good but that there is competition for the access to information, for example because an agent with many contacts must share his time between them and thus has fewer opportunities to pass on information to each particular contact. The main idea is that the probability that each neighbor receives the information decreases with the number of contacts the sender has. In the second model, we assume that there is not competition for the access to information but that the use of information is rivalrous. In this case, it is assumed that when people receive the information before me, the harmful effect is greater than when others receive the information at the same time as myself. Our results concern pairwise stability and efficiency in both models and allow us to compare and contrast the effects of two kinds of competition for information.