I undertake a quantitative investigation into the short run effects of changes in the timing of proportional income taxes for model economies in which heterogeneous households face a borrowing constraint. Temporary tax changes are found to have large real effects. In the benchmark model, a temporary tax cut increases aggregate consumption on impact by around 29 cents for every dollar of tax revenue lost. Comparing the benchmark incomplete-markets model to a complete-markets economy, income tax cuts provide a larger boost to consumption and a smaller investment stimulus when asset markets are incomplete.

Between 2007 and 2013, U.S. households experienced a large and persistent decline in net worth. The objective of this article is to study the business cycle implications of such a decline. We first develop a tractable monetary model in which households face idiosyncratic unemployment risk that they can partially self-insure using savings. A low level of liquid household wealth opens the door to self-fulfilling fluctuations: if wealth-poor households expect high unemployment, they have a strong precautionary incentive to cut spending, which can make the expectation of high unemployment a reality. Monetary policy, because of the zero lower bound, cannot rule out such expectations-driven recessions. In contrast, when wealth is sufficiently high, an aggressive monetary policy can keep the economy at full employment. Finally, we document that during the U.S. Great Recession wealth-poor households increased saving more sharply than richer households, pointing towards the importance of the precautionary channel over this period.

This paper evaluates the role of rising income inequality in explaining observed growth in college tuition. We develop a competitive model of the college market, in which college quality depends on instructional expenditure and the average ability of admitted students. An innovative feature of our model is that it allows for a continuous distribution of college quality. We find that observed increases in US income inequality can explain more than half of the observed rise in average net tuition since 1990 and that rising income inequality has also depressed college attendance.

In this paper we do two things. First we document that over the last 40 years the U.S. business cycle has become less synchronized with the cycle in the rest of the world. Second we try to explain why this has happened. We use a general-equilibrium model as a tool to discriminate between two alternative explanations: (i) a change in the nature of real shocks, and (ii) an increase in U.S. financial integration with the rest of the world. Our results indicate that financial integration has played the major role in producing the observed changes in international co-movement.

The international diversification puzzle is the fact that country portfolios are on average biased toward domestic assets, while one-good international macro models with nondiversifiable labor income risk predict the opposite pattern of diversification. This paper embeds a portfolio choice decision in a two-good international business cycle model and provides a closed-form solution for equilibrium country portfolios. Equilibrium portfolios are biased toward domestic assets because endogenous international relative price fluctuations make domestic assets a good hedge against labor income risk. Evidence from developed economies in recent years is qualitatively and quantitatively consistent with the mechanisms highlighted by the theory.

What shapes the optimal degree of progressivity of the tax and transfer system? On the one hand, a progressive tax system can counteract inequality in initial conditions and substitute for imperfect private insurance against idiosyncratic earnings risk. On the other hand, progressivity reduces incentives to work and to invest in skills, distortions that are especially costly when the government must finance public goods. We develop a tractable equilibrium model that features all of these trade-offs. The analytical expressions we derive for social welfare deliver a transparent understanding of how preference, technology, and market structure parameters influence the optimal degree of progressivity. A calibration for the U.S. economy indicates that endogenous skill investment, flexible labor supply, and the desire to finance government purchases play quantitatively similar roles in limiting optimal progressivity. In a version of the model where poverty constrains skill investment, optimal progressivity is close to the U.S. value. An empirical analysis on cross-country data offers support to the theory.

The US net foreign asset position declined sharply after 2007, reaching negative 60 percent of GDP by the third quarter of 2023. This deterioration primarily reflects a US-specific rise in corporate asset values that inflated the value of US equity liabilities to the rest of the world. To interpret these trends, we develop an international macrofinance model of flows, stocks, asset valuations, the current account, and the net foreign asset position. We find that the welfare impact of rising asset values for a representative US household has been quite negative given extensive foreign ownership of US corporate equity.

We develop a model with partial insurance against idiosyncratic wage shocks to quantify risk sharing. Closed-form solutions are obtained for equilibrium allocations and for moments of the joint distribution of consumption, hours, and wages. We prove identification and demonstrate how labor supply data are informative about risk sharing. The model, estimated with US data over the period 1967–2006, implies that (i) 39 percent of permanent wage shocks pass through to consumption; (ii ) the share of wage risk insured increased until the early 1980s; and (iii) preference heterogeneity is important in accounting for observed dispersion in consumption and hours.

In recent decades, American workers have faced a rising college premium, a narrowing gender gap, and increasing wage volatility. This paper explores the quantitative and welfare implications of these changes. The framework is an incomplete-markets life cycle model in which individuals choose education, intrafamily time allocation, and savings. Given the observed history of the U.S. wage structure, the model replicates key trends in cross-sectional inequality in hours worked, earnings, and consumption. Recent cohorts enjoy welfare gains, on average, as higher relative wages for college graduates and for women translate into higher educational attainment and a more even division of labor within the household.

We explore the optimal shape of the income tax and transfer schedule in an environment with distinct roles for public and private insurance. In a calibration to the United States, we find that the optimal system features marginal tax rates that increase in income. When we increase pressure on the government to raise revenue, the optimal marginal tax schedule becomes first flatter and then U-shaped, reconciling various findings in the literature. A power function parametric tax schedule outperforms an affine one, indicating that tax progressivity is more important than lump-sum transfers. We also explore various social welfare objectives and Pareto-improving reforms.