A wide body of empirical evidence finds that around 25 percent of fiscal stimulus payments (e.g., tax rebates) are spent on nondurable household consumption in the quarter that they are received.To interpret this fact, we develop a structural economic model where households can hold two assets: a low-return liquid asset (e.g., cash, checking account) and a high-return illiquid asset that carries a transaction cost (e.g., housing, retirement account).The optimal life-cycle pattern of portfolio choice implies that many households in the model are "wealthy hand-to-mouth": they hold little or no liquid wealth despite owning sizeable quantities of illiquid assets.They therefore display large propensities to consume out of additional transitory income, and small propensities to consume out of news about future income.We document the existence of such households in data from the Survey of Consumer Finances.A version of the model parameterized to the 2001 tax rebate episode yields consumption responses to fiscal stimulus payments that are in line with the evidence, and an order of magnitude larger than in the standard "one-asset" framework.The model's nonlinearities with respect to the size of the rebate, its degree of phasing-out, and aggregate economic conditions have implications for policy design.

Fiscal stimulus payments (i.e., direct lump-sum payments from the government to households) were used in the recessions of 2001 and 2008 in an attempt to simultaneously alleviate households' economic hardship and stimulate aggregate demand. Despite the similarities between the two stimulus policies, there were important differences in both their design and the prevailing economic conditions. We use the model of Kaplan and Violante (2013) to compare the consumption response to these policies. Consistent with empirical evidence from microdata, we find that the consumption response was around one-third lower in 2008, primarily due to the larger size of the payments.

We revisit the transmission mechanism from monetary policy to household consumption in a Heterogeneous Agent New Keynesian (HANK) model. The model yields empirically realistic distributions of wealth and marginal propensities to consume because of two features: uninsurable income shocks and multiple assets with different degrees of liquidity and different returns. In this environment, the indirect effects of an unexpected cut in interest rates, which operate through a general equilibrium increase in labor demand, far outweigh direct effects such as intertemporal substitution. This finding is in stark contrast to small- and medium-scale Representative Agent New Keynesian (RANK) economies, where the substitution channel drives virtually all of the transmission from interest rates to consumption. Failure of Ricardian equivalence implies that, in HANK models, the fiscal reaction to the monetary expansion is a key determinant of the overall size of the macroeconomic response.

This paper integrates the classic theory of firm boundaries, through span of control or taste for variety, into a model of the labor market with random matching and on‐the‐job search. Firms choose when to enter and exit, whether to create vacancies or destroy jobs in response to shocks, and Bertrand‐compete to hire and retain workers. Tractability is obtained by proving that, under a parsimonious set of assumptions, all worker and firm decisions are characterized by their joint surplus, which in turn only depends on firm productivity and size. The job ladder in marginal surplus that emerges in equilibrium determines net poaching patterns by firm characteristics that are in line with the data. As frictions vanish, the model converges to a standard competitive model of firm dynamics. The combination of firm dynamics and search frictions allows the model to: (i) quantify the misallocation cost of frictions; (ii) replicate elusive life‐cycle growth profiles of superstar firms; and (iii) make sense of the failure of the job ladder around the Great Recession as a result of the collapse of firm entry.

Does capital-embodied technological change play an important role in shaping labour-market outcomes? To address this question, we develop a model with vintage capital and search-matching frictions where irreversible investment in new vintages of capital creates heterogeneity in productivity among firms, matched as well as vacant. We demonstrate that capital-embodied technological change reduces labour demand and raises equilibrium unemployment and unemployment durations. In addition, the presence of labour-market regulations (unemployment benefits, payroll taxes, and firing costs) exacerbates these effects. Thus, the model is qualitatively consistent with some key features of the European labour-market experience relative to that of the U.S.: it features a sharper rise in unemployment and a sharper fall in the vacancy rate and the labour share. A calibrated version of our model suggests that this technology—policy interaction could explain a sizeable fraction of the observed differences between the U.S. and Europe.

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.

We develop an equilibrium model of firm dynamics with random search in the labor market where hiring firms exert recruiting effort by spending resources to fill vacancies faster. Consistent with microevidence, fast-growing firms invest more in recruiting activities and achieve higher job-filling rates. These hiring decisions of firms aggregate into an index of economy-wide recruiting intensity. We study how aggregate shocks transmit to recruiting intensity, and whether this channel can account for the dynamics of aggregate matching efficiency during the Great Recession. Productivity and financial shocks lead to sizable procyclical fluctuations in matching efficiency through recruiting effort. Quantitatively, the main mechanism is that firms attain their employment targets by adjusting their recruiting effort in response to movements in labor market slackness.

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.

We propose a new measure of frictional wage dispersion: the meanmin wage ratio. For a large class of search models, we show that this measure is independent of the wage-offer distribution but depends on statistics of labor-market turnover and on preferences. Under plausible preference parameterizations, observed magnitudes for worker flows imply that in the basic search model, and in most of its extensions, frictional wage dispersion is very small. Notable exceptions are some of the most recent models of on-the-job search. Our new measure allows us to rationalize the diverse empirical findings in the large literature estimating structural search models.