The enlargement of the general-equilibrium structure to allow default subject to penalties results in a construction of a simple mechanism for selecting a unique competitive equilibrium. We consider economies for which a common credit money can be applied to uniquely select any competitive...

Can regulation solve problems arising from a natural monopoly? This paper analyzes whether "unbundling", referring to regulations that enforce sharing of natural monopolistic infrastructure, prevents entrants from building new infrastructure. It models and estimates a dynamic entry game to...