Research Database

We provide sufficient conditions for the feasibility of a Pareto-improving fiscal policy when the risk-free interest rate on government bonds is below the growth rate (r < g) or there is a markup between price and marginal cost. We do so in the class of incomplete markets models pioneered by Bewley-Huggett-Aiyagari, but we allow for an arbitrary amount of ex ante heterogeneity in terms of preferences and income risk. We consider both the case of dynamic inefficiency as well as the more plausible case of dynamic efficiency. The key condition is that seigniorage revenue raised by government bonds exceeds the increase in the interest rate times the initial capital stock. The Pareto improving fiscal policies weakly expand every agent's budget set at every point in time. The policies improve risk sharing and potentially guide the economy to a more efficient level of capital. We establish that debt and investment associated with Pareto improving policies along the transition may be complements, rather than the traditional substitutes.

This paper presents a continuous-time model of sovereign debt. In it, a relatively impatient sovereign government’s hidden type switches back and forth between a commitment type, which cannot default, and an optimizing type, which can default on the country’s debt at any time, and assume outside lenders have particular beliefs regarding how a commitment type should borrow for any given level of debt and bond price. We show that if these beliefs satisfy reasonable assumptions, in any Markov equilibrium, the optimizing type mimics the commitment type when borrowing, revealing its type only by defaulting on its debt at random times. Further, in such Markov equilibria (the solution to a simple pair of ordinary differential equations), there are positive gross issuances at all dates, constant net imports as long as there is a positive equilibrium probability that the government is the optimizing type, and net debt repayment only by the commitment type. For countries that have recently defaulted, the interest rate the country pays on its debt is a decreasing function of the amount of time since its last default, and its total debt is an increasing function of the amount of time since its last default. For countries that have not recently defaulted, interest rates are constant.

Recently, several economies with interest rates close to zero have received large capital inflows while their central banks accumulated large foreign reserves. Concurrently, significant deviations from covered interest parity have appeared. We show that, with limited international arbitrage, a central bank's pursuit of an exchange rate policy at the ZLB can explain these facts. We provide a measure of the costs associated with this policy and show they can be sizable. Changes in external conditions that increase capital inflows are detrimental, even when they are beneficial away from the ZLB. Negative nominal rates and capital controls can reduce the costs.

We study fiscal and monetary policy in a monetary union with the potential for rollover crises in sovereign debt markets. Member-country fiscal authorities lack commitment to repay their debt and choose fiscal policy independently. A common monetary authority chooses inflation for the union, also without commitment. We first describe the existence of a fiscal externality that arises in the presence of limited commitment and leads countries to over-borrow; this externality rationalizes the imposition of debt ceilings in a monetary union. We then investigate the impact of the composition of debt in a monetary union, that is the fraction of high-debt versus low-debt members, on the occurrence of self-fulfilling debt crises. We demonstrate that a high-debt country may be less vulnerable to crises and have higher welfare when it belongs to a union with an intermediate mix of high- and low-debt members, than one where all other members are low-debt. This contrasts with the conventional wisdom that all countries should prefer a union with low-debt members, as such a union can credibly deliver low inflation. These findings shed new light on the criteria for an optimal currency area in the presence of rollover crises.

We study optimal fiscal policy in a small open economy (SOE) with sovereign and private default risk and limited commitment to tax plans. The SOE's government uses linear taxation to fund exogenous expenditures and uses public debt to inter-temporally allocate tax distortions. We characterize a class of environments in which the tax on labor goes to zero in the long run, while the tax on capital income may be non-zero, reversing the standard prediction of the Ramsey tax literature. The zero labor tax is an optimal long run outcome if the economy is subject to sovereign debt constraints and the domestic households are impatient relative to the international interest rate. The front loading of tax distortions allows the economy to build a large (aggregate) debt position in the presence of limited commitment. We show that a similar result holds in a closed economy with imperfect inter-generational altruism, providing a link with the closed-economy literature that has explored disagreement between the government and its citizens regarding inter-temporal tradeoffs.

In January 2015, in the face of sustained capital inflows, the Swiss National Bank abandoned the floor for the Swiss Franc against the Euro, a decision which led to the appreciation of the Swiss Franc. The objective of this paper is to present a simple framework that helps to better understand the timing of this episode, which we label a “reverse speculative attack". We model a central bank which wishes to maintain a peg, and responds to increases in demand for domestic currency by expanding its balance sheet. In contrast to the classic speculative attacks, which are triggered by the depletion of foreign assets, reverse attacks are triggered by the concern of future balance sheet losses. Our key result is that the interaction between the desire to maintain the peg and the concern about future losses, can lead the central bank to first accumulate a large amount of reserves, and then to abandon the peg, just as we have observed in the Swiss case.

We establish that creditor beliefs regarding future borrowing can be self-fulfilling, leading to multiple equilibria with markedly different debt accumulation patterns. We characterize such indeterminacy in the Eaton-Gersovitz sovereign debt model augmented with long maturity bonds. Two necessary conditions for the multiplicity are: (i) the government is more impatient than foreign creditors, and (ii) there are deadweight losses from default; both are realistic and standard assumptions in the quantitative literature. The multiplicity is dynamic and stems from the self-fulfilling beliefs of how future creditors will price bonds; long maturity bonds are therefore a crucial component of the multiplicity. We introduce a third party with deep pockets to discuss the policy implications of this source of multiplicity and identify the potentially perverse consequences of traditional “lender of last resort” policies.