Abstract. Modern production frequently involves teamwork among employees specialized in different tasks. I develop a model of teams in which firms assign tasks to workers who are heterogeneous in their overall quality and whose efficiency varies across different tasks. In addition to productivity gains, the division of labor generates coworker complementarities: the marginal productivity of one employee's quality is increasing in other team members' quality. This interdependence is stronger when variation in worker-task specific efficiencies is high. In frictional labor markets, coworker complementarities carry macroeconomic implications for both productivity and inequality. Coworker quality mismatch lowers team productivity, leading employers to search for workers of similar quality. In equilibrium, firms with ``superstar teams'' pull away in terms of productivity and pay. I validate the model's key mechanisms using administrative micro data. Paralleling a shift in the nature of tasks, a theory-informed measure of coworker complementarities has doubled since 1990. A structural estimation exercise suggests that this rise explains between one quarter and one half of the increase in the between-firm share of wage inequality in Germany (1990-2010).

• Keynes Fund Grant (~£9,000)

Abstract. This paper studies the role of macroeconomic uncertainty in a search-and-matching framework with risk-averse households. Heightened uncertainty about future productivity reduces current economic activity even in the absence of nominal rigidities. A risk-premium mechanism accounts for this result. As future asset prices become more volatile and covary more positively with aggregate consumption, the risk premium rises in the present. The associated downward pressure on current asset values lowers firm entry, making it harder for workers to find jobs and reducing supply. With nominal rigidities the recession is exacerbated, as a more uncertain future reinforces households’ precautionary behavior, which causes demand to contract. Counterfactual analyses using a calibrated model imply that unemployment would rise by less than half as much absent the risk-premium channel. The presence of this mechanism implies that uncertainty shocks are less deflationary than regular demand shocks, nor can they be fully neutralized by monetary policy.

• [Online Appendix], [Replication files], [Slides for SITE | September 2022]

• Also see Cambridge INET Special Feature

• Previously circulated under the title “Unexpected Effects: Uncertainty, Unemployment, and Inflation"

Abstract. In search-and-matching models, the nonlinear nature of search frictions increases average unemployment rates during periods with higher volatility. These frictions are not, however, by themselves sufficient to raise unemployment following an increase in perceived uncertainty; though they may do so in conjunction with the common assumption of wages being determined by Nash bargaining. Importantly, option-value considerations play no role in the standard model with free entry. In contrast, when the mass of entrepreneurs is finite and there is heterogeneity in firm-specific productivity, a rise in perceived uncertainty robustly increases the option value of waiting and reduces job creation.

• [Published version - open access], [Online appendix ], [Replication files], [Short slides for RES Conference | April 2021]

• [VoxEU column | September 2021]

Abstract. We propose a novel two-agent New Keynesian model to study the interaction of fiscal policy and household heterogeneity in a tractable environment. Workers can save in bonds subject to portfolio adjustment costs; firm ownership is concentrated among capitalists who do not supply labor. The model is consistent with micro data on empirical intertemporal marginal propensities to consume, and it avoids implausible profit income effects on labor supply. Relative to the traditional two-agent model, these features imply, respectively, a lower sensitivity of consumption to the composition of public financing; and smaller fiscal multipliers alongside pronounced redistributive effects.

• [Published version - open access], [Online appendix], [Replication files], [Slides]

• Coverage: centralbanking.com

• 13th Nordic Summer Symposium in Macroeconomics

• [Discussion Slides | August 2019]