Monetary Union with Voluntary Participation1
建模了一个自愿参与的货币联盟，分析其相对于协调的独立国家货币体系的优势，发现最优政策会因成员退出激励而调整，且联盟可能在某些状态下解体。
A Monetary Union is modeled as a technology that makes a surprise policy deviation impossible but requires voluntarily participating countries to follow the same monetary policy. Within a fully dynamic context, we identify conditions under which such arrangement may dominate a coordi-nated system with independent national currencies. Two new results are delivered by the voluntary participation assumption. First, optimal policy is shown to respond to the agents ’ incentives to leave the union by tilting both current and future policy in their favor. This contrasts with the static nature of optimal policy when participation is exogenously assumed and implies that policy in the union is not exclusively guided by area-wide devel-opments but does occasionally take account of member countries ’ national developments. Second we show that there might exist states of the world in which the union breaks apart, as occurred in some historical episodes. The paper thus provides a first formal analysis of the incentives behind the formation, sustainability and disruption of a Monetary Union.