Interaction et coopération en réseau. Un modèle de gratuité

Interactions between Internet users or network nodes mostly consist of requests. Thus, virtual communities and newsgroup, but also data transmission through Internet networks, rest on systems of bilateral or multilateral requests. This representation of Internet allows us to study the best strategies for the senders of requests. We show that under certain conditions, it is not optimal for the senders to reward the agents who do the requests. Hence free interaction may be a relative efficient model for Internet communities. This model is strenghtened when the senders accept to leave the results of their requests open. This framework helps to better undestand cooperative practices on Internet, like peering agreements among Internet Service Providers or open source software projects. Classification JEL : L86, H4