Reservation Wages and Unemployment Insurance

This paper argues that a risk-averse worker's after-tax reservation wage encodes all the relevant information about her welfare. This insight leads to a novel test for the optimality of unemployment insurance based on the responsiveness of reservation wages to unemployment benefits. Some existing estimates imply significant gains to raising the current level of unemployment benefits in the United States, but highlight the need for more research on the determinants of reservation wages. Our approach complements those based on Baily's (1978) test.

Liquidity and Insurance for the Unemployed

We study the optimal design of unemployment insurance for workers sampling job opportunities over time. We focus on the timing of benefits and the desirability of allowing workers to freely access a riskless asset. When workers have constant absolute risk aversion preferences, a very simple policy is optimal: a constant benefit during unemployment, a constant tax during employment, and free access to savings using the riskless asset. Away from this benchmark, for constant relative risk aversion preferences, the optimal policy involves nearly constant benefits and the welfare gains from more elaborate policies are minuscule. Our results highlight two distinct roles for policy toward the unemployed: ensuring workers have sufficient liquidity to smooth their consumption; and providing unemployment subsidies that serve as insurance against the uncertain duration of unemployment spells.

Inequality, Social Discounting and Estate Taxation

To what degree should societies allow inequality to be inherited? What role should estate taxation play in shaping the intergenerational transmission of welfare? We explore these questions by modeling altruistically-linked individuals who experience privately observed taste or productivity shocks. Our positive economy is identical to models with infinite-lived individuals where efficiency requires immiseration: inequality grows without bound and everyone's consumption converges to zero. However, under an intergenerational interpretation, previous work only characterizes a particular set of Pareto-efficient allocations: those that value only the initial generation's welfare. We study other efficient allocations where the social welfare criterion values future generations directly, placing a positive weight on their welfare so that the effective social discount rate is lower than the private one. For any such difference in social and private discounting we find that consumption exhibits mean-reversion and that a steady-state, cross-sectional distribution for consumption and welfare exists, where no one is trapped at misery. The optimal allocation can then be implemented by a combination of income and estate taxation. We find that the optimal estate tax is progressive: fortunate parents face higher average marginal tax rates on their bequests.

Managing a Liquidity Trap: Monetary and Fiscal Policy

I study monetary and fiscal policy in liquidity trap scenarios, where the zero bound on the nominal interest rate is binding. I work with a continuous-time version of the standard New Keynesian model. Without commitment, the economy suffers from deflation and depressed output. I show that, surprisingly, both are exacerbated with greater price flexibility. I examine monetary and fiscal policies that maximize utility for the agent in the model and refer to these as optimal throughout the paper. I find that the optimal interest rate is set to zero past the liquidity trap and jumps discretely up upon exit. Inflation may be positive throughout, so the absence of deflation is not evidence against a liquidity trap. Output, on the other hand, always starts below its efficient level and rises above it. I then study fiscal policy and show that, regardless of parameters that govern the value of "fiscal multipliers" during normal or liquidity trap times, at the start of a liquidity trap optimal spending is above its natural level. However, it declines over time and goes below its natural level. I propose a decomposition of spending according to "opportunistic" and "stimulus" motives. The former is defined as the level of government purchases that is optimal from a static, cost-benefit standpoint, taking into account that, due to slack resources, shadow costs may be lower during a slump; the latter measures deviations from the former. I show that stimulus spending may be zero throughout, or switch signs, depending on parameters. Finally, I consider the hybrid where monetary policy is discretionary, but fiscal policy has commitment. In this case, stimulus spending is typically positive and increasing throughout the trap.

Commitment Vs. Flexibility

This paper studies the optimal trade-off between commitment and flexibility in an intertemporal consumption/savings choice model. Individuals expect to receive relevant information regarding their own situation and tastes - generating a value for flexibility - but also expect to suffer from temptations - generating a value for commitment. The model combines the representations of preferences for flexibility introduced by Kreps (1979) with its recent antithesis for commitment proposed by Gul and Pesendorfer (2002), which nests the hyperbolic discounting model. We set up and solve a mechanism design problem that optimizes over the set of consumption/saving options available to the individual each period. We characterize the conditions under which the solution takes a simple threshold form where minimum savings policies are optimal. Our analysis is also relevant for other issues such as situations with externalities or the problem faced by a 'paternalistic' planner, which may be important for thinking about some regulations such as forced minimum schooling laws.

Insurance and Taxation over the Life Cycle

We consider a dynamic Mirrlees economy in a life-cycle context and study the optimal insurance arrangement. Individual productivity evolves as a Markov process and is private information. We use a first-order approach in discrete and continuous time and obtain novel theoretical and numerical results. Our main contribution is a formula describing the dynamics for the labour-income tax rate. When productivity is an AR(1) our formula resembles an AR(1) with a trend where: (i) the auto-regressive coefficient equals that of productivity; (ii) the trend term equals the covariance productivity with consumption growth divided by the Frisch elasticity of labour; and (iii) the innovations in the tax rate are the negative of consumption growth. The last property implies a form of short-run regressivity. Our simulations illustrate these results and deliver some novel insights. The average labour tax rises from 0% to 37% over 40 years, whereas the average tax on savings falls from 12% to 0% at retirement. We compare the second best solution to simple history-independent tax systems, calibrated to mimic these average tax rates. We find that age-dependent taxes capture a sizable fraction of the welfare gains. In this way, our theoretical results provide insights into simple tax systems

Inequality and Social Discounting

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.Economic

Slow Moving Debt Crises

What circumstances or policies leave sovereign borrowers at the mercy of self-fulfilling increases in interest rates? To answer this question, we study the dynamics of debt and interest rates in a model where default is driven by insolvency. Fiscal deficits and surpluses are subject to shocks but influenced by a fiscal policy rule. Whenever possible the government issues debt to meet its current obligations and defaults otherwise. We show that low and high interest rate equilibria may coexist. Higher interest rates, prompted by fears of default, lead to faster debt accumulation, validating default fears. We call such an equilibrium a slow moving crisis, in contrast to rollover crises where investor runs precipitate immediate default. We investigate how the existence of multiple equilibria is affected by the fiscal policy rule, the maturity of debt, and the level of debt

A Theory of Capital Controls as Dynamic Terms-of-Trade Manipulation

We develop a theory of capital controls as dynamic terms-of-trade manipulation. We study an infinite-horizon endowment economy with two countries. One country chooses taxes on international capital flows in order to maximize the welfare of its representative agent, while the other country is passive. We show that a country growing faster than the rest of the world has incentives to promote domestic savings by taxing capital inflows or subsidizing capital outflows. Although our theory of capital controls emphasizes interest rate manipulation, the pattern of borrowing and lending, per se, is irrelevant