Monetary Union with Voluntary Participation

A Monetary Union is modeled as a technology that makes a surprise policy deviation impossible and 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 coordinated 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 yields a non-linear rule according to which each country's weight in policy decisions is time-varying and depends on the incentives to abandon the union. Second we show that there might conditions such that a break-up of the union, as occurred in some historical episodes, is efficient. The paper thus provides a first formal analysis of the incentives behind the formation, sustainability and disruption of a Monetary Union.