. We approach this omission by analyzing the role of positive and negative externalities of link formation. This yields … general results that relate situations of positive externalities with stable networks that cannot be too dense in a well …-defined sense, while situations with negative externalities tend to induce too dense networks. …

encompasses many economic models with externalities and outside options. We show that when outside options are pure (i …

Consider an environment with widespread externalities, and suppose that binding agreements can be written. We study …

externalities. An organization is defined as a group of agents, together with a set of bilateral relations, formally, a connected … graph. Because of the presence of externalities, the profitability of coalitional threats to an organization depend on the … externalities, while the fully connected organization emerges under negative. This result is shown to hold independently of the …

We study two n-player sequential network formation games with externalities. Link formation is tied to simultaneous … sufficient conditions for efficiency in terms of cyclical monotonicity. The n-player group version always yields efficiency. …

environmental problems. Second it summarises important findings which help to explain the difficulties of co-operation and discusses …