Sovereign risk premia in several euro area countries have risen markedly since 2008, driving up credit spreads in the private sector as well. We propose a New Keynesian model of a two-region monetary union that accounts for this “sovereign risk channel.” The model is calibrated to the euro area as of mid-2012. We show that a combination of sovereign risk in one region and strongly procyclical fiscal policy at the aggregate level exacerbates the risk of belief-driven deflationary downturns. The model provides an argument in favor of coordinated, asymmetric fiscal stances as a way to prevent selffulfilling debt crises.

In this paper we show that a currency area can be a self-validating optimal policy regime, even when monetary unification does not foster real economic integration and intra-industry trade. This is because profit-maximizing producers in a currency area adopt endogenous pricing strategies that make exchange rate fluctuations highly costly in welfare terms. In our model exporters choose the degree of exchange rate pass-through onto export prices given monetary policy rules, and monetary authorities choose optimal policy rules taking firms' pass-through as given. We show that there exist two equilibria, which define two self-validating currency regimes. In the first, firms preset prices in domestic currency only, and let foreign-currency prices to be determined by the law of one price. Optimal policy rules then target the domestic output gap and floating exchange rates support the flex-price allocation. In the second equilibrium firms optimally preset prices in local currency, and a monetary union is the optimal policy choice for all countries. Although business cycles are more synchronized with a common currency, flexible exchange rates are superior in terms of welfare.

This paper analyzes the impact of strained government finances on macroeconomic stability and the transmission of fiscal policy. Using a variant of the model by Curdia and Woodford (2009), we study a "sovereign risk channel" through which sovereign default risk raises funding costs in the private sector. If monetary policy is constrained, the sovereign risk channel exacerbates indeterminacy problems: private-sector beliefs of a weakening economy may become self-fulfilling. In addition, sovereign risk amplifies the effects of negative cyclical shocks. Under those conditions, fiscal retrenchment can help curtail the risk of macroeconomic instability and, in extreme cases, even stimulate economic activity.

This paper provides a baseline general-equilibrium model of optimal monetary policy among interdependent economies, with monopolistic firms that set prices one period in advance. Strict adherence to inward-looking policy objectives such as the stabilization of domestic output cannot be optimal when firms' markups are exposed to currency fluctuations. Such policies induce excessive volatility in exchange rates and foreign sales revenue, leading exporters to set higher prices in response to higher profit risk. In general, optimal rules trade off a larger domestic output gap against lower import prices. Monetary rules in a world Nash equilibrium lead to smaller exchange rate volatility relative to both inward-looking rules and discretionary policies, even when the latter do not suffer from any inflationary (or deflationary) bias. Gains from international monetary cooperation are related in a non-monotonic way to the degree of exchange rate pass-through.

It is often argued that the provision of liquidity by the international institutions such as the IMF to countries experiencing balance of payment problems can have catalytic effects on the behavior of international financial markets, i.e., it can reduce the scale of liquidity runs by inducing investors to roll over their financial claims to the country. Critics point out that official lending also causes moral hazard distortions: expecting to be bailed out by the IMF, debtor countries have weak incentives to implement good but costly policies, thus raising the probability of a crisis. This paper presents an analytical framework to study the trade-off between official liquidity provision and debtor moral hazard. In our model international financial crises are caused by the interaction of bad fundamentals, self-fulfilling runs and policies by three classes of optimizing agents: international investors, the local government and the IMF. We show how an international financial institution helps prevent liquidity runs via coordination of agents' expectations, by raising the number of investors willing to lend to the country for any given level of the fundamental. We show that the influence of such an institution is increasing in the size of its interventions and the precision of its information: more liquidity support and better information make agents more willing to roll over their debt and reduces the probability of a crisis. Different from the conventional view stressing debtor moral hazard, we show that official lending may actually strengthen a government incentive to implement desirable but costly policies. By worsening the expected return on these policies, destructive liquidity runs may well discourage governments from undertaking them, unless they can count on contingent liquidity assistance.

Is the seniority structure of sovereign debt neutral for a government's decision between defaulting and raising surpluses? In this paper, we address this question using a model of debt crises where a discretionary government endogenously chooses distortionary taxation and whether to apply an optimal haircut to bondholders. We show that when the size of senior tranches is small, a version of the Modigliani-Miller theorem holds: tranching just redistributes government revenues from junior to senior bondholders, while taxes and government borrowing costs remain unchanged. However, as senior tranches become sufficiently large, default costs on senior debt transpire into a stronger commitment to repay not only the senior tranche, but also the junior one. We show that there is a lower threshold for senior bonds above which tranching can eliminate default on both junior and senior debt, and an upper threshold beyond which the government defaults also on senior debt.