Esternalita' di rete: una riformulazione del modello di Fukao in termini di giochi supermodulari

Coordination failures are very important in imperfect markets, because of related concept of multiple equilibria. This article attempts to explore this topic using tools to overcome the limitations of traditional analytical apparatus, which imposes stringent conditions about functions and strategy sets. The paper reports the general concepts of global games, summarizes the key findings of a global game with network externalities developed by K. Fukao and esplicates the basic concepts of lattice theory and supermodular games. In the reformulation of Fukao model the work uses a no-convex strategy set: it provides existence of at least an equilibrium and obtains result with easier calculation. The lattice-theoretic methodology is applied to study multiple equilibria in a greater class of models.