Competitive equilibria with limited enforcement

We show how to decentralize constrained efficient allocations that arise from enforcement constraints between sovereign nations. In a pure exchange economy these allocations can be decentralized with private agents acting competitively and taking as given government default decisions on foreign debt. In an economy with capital these allocations can be decentralized if the government can tax capital income as well as default on foreign debt. The tax on capital income is needed to make private agents internalize a subtle externality. The decisions of the government can arise as an equilibrium of a dynamic game between governments.     

Public debt in a basic endogenous growth model

We work out the mechanism that makes public debt affect the allocation of resources in the long-run. To do so we analyze an AK growth model with elastic labor supply and a government sector. The government levies a distortionary income tax and issues bonds to finance lump-sum transfers and non-distortionary public spending. We show that the long-run growth rate is the smaller the higher the debt ratio if the government adjusts public spending to fulfill its inter-temporal budget constraint. If the government adjusts lump-sum transfers the public debt ratio does not affect the balanced growth rate.     

Sovereign debt spread and default in a model with self-fulfilling prophecies and asymmetric information

The euro area sovereign debt crisis has renewed interest in government credibility and the risk of default. Recent empirical evidence has shown that the sharp increase in government bond yields cannot be attributed entirely to changes in macroeconomic fundamentals. Contagion effects can occur, and self-fulfilling speculation may arise. In this paper, we develop a theoretical model in the spirit of the second-generation currency crisis models developed by Obstfled (1996). The model describes a strategic game between governments and private investors. Euro area countries face a trade-off as governments may either commit to and implement restrictive fiscal policies or default on debt. The commitment strategy may not be optimal if the fundamentals deteriorate. The policy maker lose part of their credibility, and governments are forced to default. In addition, we introduce uncertainty about the cost of default in the model, which is then able to account for a greater variety of equilibrium. Thus, when the evaluation of the cost of default is asymmetric, prophecies are not always realized and default does not occur. Simulations of the model then show that it offers insights, and can help to account for the situations of Greece and Italy during the sovereign debt crisis.     

Existence of equilibrium in an overlapping-generations model with government debt

The Diamond overlapping generations (OLG) model with government debt has been widely utilized in economics, but the existence of the steady-state equilibrium is either assumed or illustrated numerically. This paper provides easily checkable conditions for the existence and uniqueness of steady-state equilibrium in this model. By checking the first derivatives of the production and utility functions and their interactions, we can determine whether the model has a nontrivial equilibrium or not. We show that the level of government debt, production technology, individual preference, and the growth rate are important for the existence of equilibrium. If government debt exceeds a certain level, equilibrium will not exist. Given technology, preference, and the growth rate, the upper-bounds of the government debt-output ratio in equilibrium can be determined based on our results.     

Dollarization and financial integration

How does a country's exchange rate regime impact its ability to borrow from abroad? We build a small open economy model in which the government responds to shocks by adjusting monetary policy and foreign borrowing. Sovereign borrowing is subject to endogenous limits, which ensure repayment when the default punishment corresponds to financial autarky. Dollarizing implies renouncing monetary policy, but can make access to international debt markets more valuable, thereby loosening borrowing constraints. This mechanism linking dollarization to financial integration is consistent with observed declines in spreads on foreign-currency debt in countries adopting the dollar or the euro.     

Country Default Risk: An Empirical Assessment

We provide benchmarks to evaluate what is an optimal foreign debt and a maximal foreign debt ( debt-max ), when risk is explicitly considered. When the actual debt exceeds debt-max , then the economy will default when a 'bad shock' occurs. This paper is an application of the stochastic optimal controls models of Fleming and Stein (2001), which gives empirical content to the question of how one should measure 'vulnerability' to shocks, when there is uncertainty concerning the productivity of capital. We consider two sets of high-risk countries during the period 1978–99: a subset of 21 countries that defaulted on the debt, and another set of 13 countries that did not default. Default is a situation where the firms or government of a country reschedule the interest/principal payments on the external debt. We thereby explain how our analysis can anticipate default risk, and add another dimension to the literature of early warning signals of default/credit risk.     

Monetary base and federal government debt in the long-run: A non-linear analysis

Government bonds are usually traded between the financial institutions and the Fed during the open market operations. These operations impact the bank reserves, subsequently influencing the monetary base. The monetary base and government bonds may portray a common trend and government debt could potentially bind the central bank to debt monetization. This paper, using monthly data on federal government debt and the monetary base from 1947:1 to 2018:10, investigates the presence of a long-run equilibrium relationship between the two variables and as to how the long-run equilibrium relationship vary in the short-run. Threshold cointegration tests find evidence of a long-run equilibrium relationship. Estimates of the threshold vector error-correction model find statistically significant evidence of contraction in the monetary base growth in the short-run in regime 1. In regime 2, the growth in the monetary base does not adjust to accommodate faster government debt growth. These estimates find no evidence of debt monetization or otherwise in either of the regimes in the United States. The Fed, by reducing the monetary base, perhaps focuses more on the inflation target. The findings also suggest a potential scenario where the Fed and the fiscal authority are not conjoined with each other in their operations.     

Regulating collateral-requirements when markets are incomplete

In this paper we examine the effects of default and collateral on risk sharing. We assume that there is a large set of assets which all promise a risk less payoff but which distinguish themselves by their collateral requirements. In equilibrium agents default, the assets have different payoffs, and there are as many linearly independent assets available for trade as there are states of the world. We derive necessary and sufficient conditions for equilibria to be Pareto-efficient in the presence of uncertainty. We explore some examples for which the collateral equilibrium allocation is identical to the Arrow–Debreu allocation, either when agents have a high preference for the durable good, or when the endowment distribution of the durable good is relatively homogeneous. We examine a series of examples to understand which collateral-levels prevail in equilibrium and under which conditions there is scope for regulating margin-requirements, that is, restricting the sets of tradable assets through government intervention. In these examples equilibrium is always sub-optimal but regulation never leads to a Pareto-improvement. While the competitive equilibria are constrained efficient, there do exist regulations which make large groups of agents in the economy better off. These regulations typically restrict all trades to take place in the low-collateral loans and benefit the poor and the rich agents in the economy through their effects on the equilibrium interest rate and the equilibrium prices of the durable goods.     

Testing for fiscal sustainability: New evidence from the G-7 and some European countries

Whether or not a government deficit is sustainable has important implications for policy. If the debt of a nation is sustainable, then it implies that the government should have no incentive to default on its internal debt. In this article we examine whether or not the debt-GDP ratios of the G-7 and some European countries can be characterized by a unit root process with the non-linear trend and asymmetric adjustment. The econometric methodology allows us to determine whether the stationarity holds for the government's debt–GDP ratio after considering the non-linear trend. Among the main results, it is found that it is very likely that the debt–GDP ratios of Canada, Germany, the US and Italy are stationarity after taking account of the non-linear trend in the long run. Nevertheless, it is model-dependent for the debt–GDP ratios of these countries to be asymmetrically adjusted after taking the non-linear trend into consideration.     

公共资本投资、内生经济增长与合理政府债务规模*

本文基于一个具有内生增长机制的三部门世代交叠模型,讨论了政府举债为公共投资进行融资时经济的长期均衡;同时,通过数值模拟方法考察了我国的均衡政府债务规模及其影响因素。结果表明：在特定条件下,经济系统存在一个正的均衡政府债务-产出比重,该债务比重水平明显受到公共投资—产出比重、公共投资的债务融资比重、民间资本产出弹性等参数的影响。但是,均衡政府债务比重并不是无限上升的,当上述参数超过特定临界值时,经济系统无法达到均衡,政府债务-产出之比将持续上升,财政将不可持续。另外,当民间资本产出弹性较低时,较高的均衡政府债务比重可能导致经济运行动态无效率。数值模拟结果还显示,基于不同的假设情形,我国的均衡政府债务-产出比重均在不同程度上高于当前实际的政府债务规模,这为我国在未来期间实施扩张性财政政策提供了有利的依据。     

Fiscal Rules,Interest Payments on Debt,and the Irrelevance of the Taylor Principle

We show that in New Keynesian models with non‐neutral government debt, the Taylor principle ceases to be relevant for equilibrium determinacy if the government follows a fiscal rule of levying taxes in proportion to its interest payments on existing debt. This is in contrast with previous studies, which typically have assumed that taxes respond to the level of debt, and have found either a confirmation or reversal of the Taylor principle depending on the feedback from debt to taxes. We find, instead, that the equilibrium effect of the interest rate on debt is crucial for determinacy. If, as in our model, taxes are raised in response to debt interest payments, the range of indeterminacy monotonically decreases with the fiscal feedback parameter. When interest payments are completely tax‐financed, indeterminacy is ruled out without any restrictions on monetary policy.     

Exchange rate policy under sovereign default risk

We examine monetary policy options for a small open economy where sovereign default might occur due to intertemporal insolvency. Under interest rate policy and floating exchange rates the equilibrium is indetermined. Under a fixed exchange rate the equilibrium is uniquely determined and independent of sovereign default.     

FISCAL SUSTAINABILITY OF JAPAN: A DYNAMIC STOCHASTIC GENERAL EQUILIBRIUM APPROACH

The purpose of this paper is to investigate the fiscal sustainability of Japan by applying a dynamic stochastic general equilibrium model to the Japanese economy. By introducing intermediation costs into the model, we succeed in explaining the observed relationship between the interest and GDP growth rates, which is crucial in testing for sustainability. When the projected real growth rate is 2.5%, the average real interest rate becomes 2.57%, and the debt‐to‐GDP ratio gradually increases stochastically so that government debt is not sustainable. To recover sustainability, the primary surplus must be 0.2% of GDP.     

The fiscal theory of the price level and initial government debt

It is widely believed that the Fiscal Theory of the Price Level (FTPL) does not work in an environment in which initial government debt is zero. This paper demonstrates that this view is incorrect when the government issues a set of financial assets restricted to standard nominal debt contracts and money. In particular, it is possible to define a non-Ricardian fiscal policy for which the set of equilibrium price sequences under non-Ricardian fiscal policy is a proper subset of the set of equilibrium price sequences under Ricardian fiscal policy.     

LEVERAGED BUYBACKS OF SOVEREIGN DEBT: A MODEL AND AN APPLICATION TO GREECE

The model presented in this article shows that the outcome of a leveraged buyback of sovereign debt depends on the priority structure of the deal. If the institution lending the funds needed for the buyback is senior, the debtor country benefits from the deal: the government debt is reduced, implying a lower probability of default; at the same time, the deal makes the price of outstanding bonds go down, since their recovery rate declines. The opposite holds if the lending institution is junior. If the loan is underpriced, the implied subsidy is shared between the borrowing country and its bondholders, who can benefit from a price increase of their bonds. This is actually what happened with the buyback of Greek sovereign bonds in 2012, as it is shown in the empirical section. Those results do not depend on the share of country's endowment devoted to debt repayment, which instead plays a crucial role in shaping the outcome of unlevered buybacks. (JEL F34, H63)     

可持续公共债务水平下的政府违约问题研究

现实经济中存在公共债务具有可持续性时却发生政府违约的现象,本文在政府未来收支波动具有不确定性的假设下,建立一个政府与投资者的重复博弈模型以分析这一现象,研究发现:公共债务可持续性并不能完全排除政府违约风险,在政府未来基本盈余不确定的条件下,理性投资者愿意持有的公共债务水平远低于可持续的公共债务水平,两者的差异取决于政府对未来基本盈余的控制能力.     

Fiscal limits and monetary policy: default vs. inflation

This paper studies the monetary policy trade-off between low inflation and low sovereign risk in the environment where fiscal authorities fail to fully ensure the sustainability of government debt. Building on the Fiscal Theory of Price Level (FTPL) and the Fiscal Theory of Sovereign Risk (FTSR), this paper differs in its baseline assumption about the monetary policy objective, which is neither to rule out defaults regardless of inflation costs (as in FTPL), nor to follow inflation targeting regardless of associated sovereign risk (as in FTSR). Instead, we study the case in which the central bank controls the risky interest rate to minimize the probability of default while ruling out large inflation hikes. We show that this policy regime can mitigate default risks only when the central bank is expected to allow sufficient increases in inflation. When agents believe that the central bank's tolerance toward inflation hikes has increased, equilibrium risk premium goes down, suggesting that information concerning changes in the central bank's preferences over inflation directly impacts default risks.     

Self-fulfilling crises with default and devaluation

We characterize optimal debt policy in a dynamic stochastic general equilibrium model of defaults and devaluations in which self-fulfilling crises can arise. When the government cannot commit to repay its debt and cannot commit to maintain the exchange rate, consumers’ expectations of devaluation make the safe level of government debt very low. We show that, when the debt is in the crises zone—where self-fulfilling crisis can occur—the government finds it optimal to reduce the debt to exit the zone. The lower the probability that consumers assign to devaluation, however, the greater is the number of periods that the government will choose to take to exit the crisis zone. We argue that our model can help understand events in Argentina in 2001–2002 and throw light on some aspects of the current EMU sovereign debt crisis.     

“CONVENTIONAL” MONETARY POLICY IN OLG MODELS: REVISITING THE ASSET-SUBSTITUTION CHANNEL

Conventional monetary policy involves actions by the monetary and fiscal authorities: the former sets a nominal interest rate and the latter sets lump-sum taxes to finance the implied flow of interest payments on government debt. We model such policy within an overlapping generations framework and show that absent any other frictions the magnitude of the nominal interest rate gives rise to asset substitution between government debt and either private debt or capital—substitution that has both real and nominal effects. Such substitution is not in standard New Keynesian models because their dynastic specification implies that government debt is not net wealth.     

Endogenous fertility,Ricardian equivalence,and debt management policy

This paper develops a model in which dynastic families optimally determine fertility. Government debt represents a tax on future generations and on childbearing; the Ricardian Equivalence Hypothesis does not hold. Debt is welfare reducing in that it distorts the fertility decision. An increase in government debt induces a decline in fertility and an increase in the steady state capital/labor ratio. If a government inherits an existing stock of debt, the 1st-best policy is to eliminate the debt immediately. In other situations the optimal debt management policy will not, in general, entail a total elimination of the debt.