According to the Lucas-Stokey result, a government can structure its debt maturity to guarantee commitment to optimal fiscal policy by future governments. In this paper, we overturn this conclusion, showing that it does not generally hold in the same model and under the same definition of time consistency as in Lucas-Stokey. Our argument rests on the existence of an overlooked commitment problem that cannot be remedied with debt maturity: a government in the future will not necessarily tax above the peak of the Laffer curve, even if it is ex ante optimal to do so.
This thesis consists of two independent chapters. The first chapter investigates the effects of a change in the taxation system from joint to separate taxation on households’ labour supply, patterns of human capital formation, and intra-household allocations of consumption between primary and secondary earners. Household behaviour is described by an inter-temporal version of the collective household model, where household members’ relative bargaining power determines intra-household allocations of consumption. Household members have limited commitment over future allocations, and their bargaining power evolves endogenously in response to changes in the gains from marriage. The tax reform is shown to cause an internal redistribution of consumption from primary to secondary earners in households where the bargaining power of secondary earners is low. Following a switch from joint to separate taxation, secondary earners’ labour supply and stock of human capital are increased, which raises their value of divorce against the value of staying in the marriage. This translates into a higher bargaining power in the couple, and thus a higher share of secondary earners’ consumption in the household. The second chapter studies optimal monetary policy under loose commitment in a model with staggered price and wage setting. Under loose commitment, the policymaker commits to a policy plan but occasionally reneges on past promises with an exogenously given probability. The probability of commitment is common knowledge to the rational agents in the model, which makes central bank credibility imperfect. The loose commitment framework allows the researcher to investigate the relationship between credibility and welfare losses, measured by deviations of output gap and inflation from their targets. When a central bank marginally increases its credibility, welfare losses are reduced. The welfare gain is largely independent on the initial credibility level. Moreover, the output-inflation stabilisation trade-off and the response of endogenous variables to exogenous shocks change with the degree of commitment.
This paper develops a model of optimal government debt maturity in which the government cannot issue state-contingent bonds and cannot commit to fiscal policy. If the government can perfectly commit, it fully insulates the economy against government spend- ing shocks by purchasing short-term assets and issuing long-term debt. These positions are quantitatively very large relative to GDP and do not need to be actively managed by the government. Our main result is that these conclusions are not robust to the introduction of lack of commitment. Under lack of commitment, large and tilted debt positions are very expensive to finance ex-ante since they exacerbate the problem of lack of commitment ex-post. In contrast, a flat maturity structure minimizes the cost of lack of commitment, though it also limits insurance and increases the volatility of fiscal policy distortions. We show that the optimal time-consistent maturity structure is nearly at because reducing average borrowing costs is quantitatively more important for welfare than reducing fiscal policy volatility. Thus, under lack of commitment, the government actively manages its debt positions and can approximate optimal policy by confining its debt instruments to consols.
This paper builds a unified model of sovereign debt, default risk, and news shocks. News shocks improve the quantitative performance of the sovereign default model in a number of empirically-relevant dimensions. First, with news shocks, not all defaults occur during downturns. Second, the news shocks help account for key differences between developing and more developed economies: as the precision of news improves, the model predicts lower variability of consumption, less countercyclical trade balance and interest rate spreads, as well as a higher level of debt in line with more developed economies. Third, the model captures the hump-shaped relationship between default rates and the precision of news obtained from the data. Finally, the news shocks have a nonmonotonic effect on welfare.
This paper proposes a method and a toolkit for solving optimal policy with imperfect commitment. As opposed to the existing literature, our method can be employed in the medium- and large-scale models typically used in monetary policy. We apply our method to the Smets and Wouters model [American Economic Review 97(3), 586–606 (2007)], for which we show that imperfect commitment has relevant implications for interest rate setting, the sources of business cycle fluctuations, and welfare.
Yes, it makes a lot of sense. This paper studies how to design simple loss functions for central banks, as parsimonious approximations to social welfare. We show, both analytically and quantitatively, that simple loss functions should feature a high weight on measures of economic activity, sometimes even larger than the weight on inflation. Two main factors drive our result. First, stabilising economic activity also stabilises other welfare-relevant variables. Second, the estimated model features mitigated inflation distortions due to a low elasticity of substitution between monopolistic goods and a low interest rate sensitivity of demand. The result holds up in the presence of measurement errors, with large shocks that generate a trade-o¤ between stabilising inflation and resource utilisation, and also when imposing a moderate degree of interest rate volatility.
Monetary policy objectives and targets are not necessarily constant over time. The regime-switching literature has typically analyzed and interpreted changes in policymakers' behavior through simple interest rate rules. This paper analyzes policy regime switches by explicitly modeling policymakers' behavior and objectives. We show that changes in the parameters of simple rules do not necessarily correspond to changes in policymakers' preferences. In fact, capturing and interpreting regime changes in preferences through interest rate rules can lead to misleading results.
Due to time-inconsistency or political turnover, policymakers' promises are not always fulfilled. We analyze an optimal fiscal policy problem where the plans made by the benevolent government are periodically revised. In this loose commitment setting, the properties of labor and capital income taxes are significantly different than under the full-commitment and no-commitment assumptions. Because of the occasional reoptimizations, the average capital income tax is positive even in the long-run. Also, the autocorrelation of taxes is lower, their volatility with respect to output increases and the correlation between capital income taxes and output changes sign. Our method can be used to analyze the plausibility and the importance of commitment in a wide-class of dynamic problems.
As the nominal interest rate cannot fall below zero, a central bank with imperfect credibility faces a significant challenge to stabilize the economy in a New Keynesian model during a large recession. We characterize the optimal monetary policy at the zero lower bound for the nominal interest rate if credibility is imperfect. Confronting monetary policy communication of the U.S. Federal Reserve and the Swedish Riksbank with such a framework, the credibility of both institutions is shown to have been low in the aftermath of the 2008 economic crisis.
We estimate and compare two models in which households periodically update their expectations. The first model assumes that households update their expectations towards survey measures. In the second model, households update their expectations towards rational expectations (RE). While the literature has used these specifications indistinguishably, we argue that there are important differences. The two models imply different updating probabilities, and the data seem to prefer the second one. We then analyse the properties of both models in terms of mean expectations, median expectations, and a measure of disagreement among households. The model with periodical updates towards RE also seems to fit the data better along these dimensions.
The tendency of countries to accumulate public debt has been rationalized in models of political disagreement and lack of commitment. We analyze in a benchmark model how the evolution of public debt is affected by lack of commitment per se. While commitment introduces indeterminacy in the level of debt, lack of commitment creates incentives for debt to converge to specific levels. One of the levels that debt often converges to implies no debt accumulation at all. In a simple example we prove analytically that debt converges to zero, and we analyze numerically more complex models. We also show in an imperfect credibility setting that a small deviation from full-commitment is enough to obtain these results.
We propose a framework in which expectations have a rational and a learning component. We describe a solution method for these frameworks and provide an application to the Volcker disinflation with the New Keynesian model. Although the model with rational expectations does not seem to account for this episode, results improve when a small and empirically plausible proportion of private agents are learning. The learning component is argued to be more robust and plausible than the rule-of-thumb expectations present in the hybrid Phillips curve.
This paper estimates the Phillips curve allowing for a simultaneous role of rational and survey expectations. We consider both a reduced form and a structural specification of the Phillips curve. The results suggest that survey expectations can be a statistically significant component of firms' expectations and inflation dynamics. However, rational expectations continue to play a dominant role.
This paper asks whether interest rate rules that respond aggressively to inflation, following the Taylor principle, are feasible in countries that suffer from fiscal dominance. We find that if interest rates are allowed to also respond to government debt, they can produce unique equilibria. But such equilibria are associated with extremely volatile inflation. The resulting frequent violations of the zero lower bound make such rules infeasible. Even within the set of feasible rules the welfare optimizing response to inflation is highly negative. The welfare gain from responding to government debt is minimal compared to the gain from eliminating fiscal dominance.