Abstract : During the past decade, the study of networks has been a very active area of research in economics. It is now largely admitted that they play a central role in the decentralized transmission of information among individuals. Information pieces that agents communicate about range from vacant job opportunities to the state of the market a team of workers is facing. This thesis aims at shedding a new light on the link between the way agents strategically share private information and the structure of the networks they are arranged in. The application of non-cooperative game theory to the study of social and economic networks has mainly been twofold: on the one hand, Network Games consider that players are the members of a given network and investigate how strategic behaviors and economic outcomes are influenced by the architecture of this network; on the other hand, Network Formation Games model the strategic building of connections between players. The present work yields new insights in these two research areas. In the first part of my thesis, made up of Chapter 1 entitled Centralizing Information in Networks, players belong to a given network which effects the waythey transmit private information items. In the second part, made up of Chapters 2 and 3 and entitled Strategic Communication Networks, the network tructure is derived from strategic communication between players.