We study the optimal inflation tax in an economy with heterogeneous agents subject to nonlinear taxation of labor income. We find that the Friedman rule is Pareto efficient when combined with a nondecreasing labor income tax. In addition, the optimum for a utilitarian social welfare function lies on this region of the Pareto frontier. The welfare costs from inflation are bounded below by the area under the demand curve.

The empirical observation that “large firms tend to export, whereas small firms do not” has transformed the way economists think about the determinants of international trade. Yet, it has had surprisingly little impact on how economists think about trade policy. Under very general conditions, we show that from the point of view of a country that unilaterally imposes trade taxes to maximize domestic welfare, the self‐selection of heterogeneous firms into exports calls for import subsidies on the least profitable foreign firms. In contrast, our analysis does not provide any rationale for export subsidies or taxes on the least profitable domestic firms.

We study the optimal trade-off between commitment and flexibility in a consump- tion-savings model. Individuals expect to receive relevant information regarding tastes and thus they value the flexibility provided by larger choice sets. On the other hand, they also expect to suffer from temptation, with or without self-control, and thus they value the commitment afforded by smaller choice sets. The optimal commitment problem we study is to find the best subset of the individual's budget set. This problem leads to a principal-agent formulation. We find that imposing a minimum level of savings is always a feature of the solution. Necessary and sufficient conditions are derived for minimum-savings policies to completely characterize the solution. We also discuss other applications, such as the design of fiscal constitutions, the problem faced by a paternalist, and externalities. Copyright The Econometric Society 2006.

The theory of comparative advantage is at the core of neoclassical trade theory. Yet we know little about its implications for how nations should conduct their trade policy. For example, should import sectors with weaker comparative advantage be protected more? Conversely, should export sectors with stronger comparative advantage be subsidized less? In this article we take a first stab at exploring these issues. Our main results imply that in the context of a canonical Ricardian model, optimal import tariffs should be uniform, whereas optimal export subsidies should be weakly decreasing with respect to comparative advantage, reflecting the fact that countries have more room to manipulate prices in their comparative-advantage sectors. Quantitative exercises suggest substantial gains from such policies relative to simpler tax schedules.

Is the standard hyperbolic†discounting model capable of robust qualitative predictions for savings behavior? Despite results suggesting a negative answer, we provide a positive one. We give conditions under which all Markov equilibria display either saving at all wealth levels or dissaving at all wealth levels. Moreover, saving versus dissaving is determined by a simple condition comparing the interest rate to a threshold made up of impatience parameters only. Our robustness results illustrate a well†behaved side of the model and imply that qualitative behavior is determinate, dissipating indeterminacy concerns to the contrary (Krusell and Smith, 2003). We prove by construction that equilibria always exist and that multiplicity is present in some cases, highlighting that our robust predictions are not due to uniqueness. Similar results may be obtainable in related dynamic games, such as political economy models of public spending.

We study slow moving debt crises: self-fulfilling equilibria in which high interest rates, due to the fear of a future default, lead to a gradual but faster accumulation of debt, ultimately validating investors’ fear. We show that slow moving crises arise in a variety of settings, both when fiscal policy follows a given rule and when it is chosen by an optimizing government. A key assumption, in all these settings, is that the borrowing government cannot commit to issue a fixed amount of bonds in a given period. We discuss how multiplicity is avoided for low debt levels, for sufficiently responsive fiscal policy rules, and for long enough debt maturities. When the equilibrium is unique, debt dynamics are characterized by a tipping point, below which debt falls and stabilizes and above which debt and default rates grow.

This paper extends the benchmark New-Keynesian model by introducing two frictions: (i) agent heterogeneity with incomplete markets, uninsurable idiosyncratic risk, and occasionally-binding borrowing constraints; and (ii) bounded rationality in the form of level-k thinking. Compared to the benchmark model, we show that the interaction of these two frictions leads to a powerful mitigation of the effects of monetary policy, which is more pronounced at long horizons, and offers a potential rationalization of the “forward guidance puzzle.” Each of these frictions, in isolation, would lead to no or much smaller departures from the benchmark model.

We develop a theory of optimal estate taxation in a model where bequest inequality is driven by differences in parental altruism. We show that a wide range of results are possible, from positive taxes to subsidies. The results depend on redistributive objectives implicit in the cardinal specification of utility and social welfare functions. We propose a normalization that is helpful in classifying these different possibilities. We isolate cases where the optimal policy bans negative bequests and taxes positive bequests, features present in most advanced countries.

Economies with private information provide a rationale for capital taxation. In this paper we ask what the welfare gains from following this prescription are. We develop a method to answer this question in standard general equilibrium models with idiosyncratic uncertainty and incomplete markets. We find that general equilibrium forces are important and greatly reduce the welfare gains. Once these effects are taken into account, the gains are relatively small in our benchmark calibration. These results do not imply that dynamic aspects of social insurance design are unimportant, but they do suggest that capital taxation may play a modest role.

We explore steady‐state inequality in an intergenerational model with altruistically linked individuals who experience privately observed taste shocks. When the welfare function depends only on the initial generation, efficiency requires immiseration: inequality grows without bound and everyone’s consumption converges to zero. We study other efficient allocations in which the welfare function values future generations directly, placing a positive but vanishing weight on their welfare. The social discount factor is then higher than the private one, and for any such difference we find that consumption exhibits mean reversion and that a steady‐state, cross‐sectional distribution for consumption and welfare exists, with no one trapped at misery.