We study optimal product market interventions in an unequal economy in which firm ownership is concentrated and markups increase with firm market shares. We characterize optimal regulation in a static Mirrleesian setting in which we impose no constraints on the shape of interventions, and take...

We study the welfare costs of markups in a dynamic model with heterogeneous firms and endogenously variable markups. We find that the welfare costs of markups are large. We decompose the costs of markups into three channels: (i) an aggregate markup that acts like a uniform output tax, (ii)...

Modern business cycle theory focuses on the study of dynamic stochastic general equilibrium models that generate aggregate fluctuations similar to those experienced by actual economies. We discuss how this theory has evolved from its roots in the early real business cycle models of the late...

Recent studies say prices change every four months. Economists have interpreted this high frequency as evidence against the importance of sticky prices for the monetary transmission mechanism. Theory implies that if most price changes are regular, as they are in the standard New Keynesian model,...

This paper examines the role of inventories in the decline of production, trade, and expenditures in the US in the economic crisis of late 2008 and 2009. Empirically, we show that international trade declined more drastically than trade-weighted production or absorption and there was a sizeable...

The large, persistent fluctuations in international trade that can not be explained in standard models by changes in expenditures and relative prices are often attributed to trade wedges. We show that these trade wedges can reflect the decisions of importers to change their inventory holdings....

We study a model of industry dynamics in which idiosyncratic risk is uninsurable and establishments are subject to a financing constraint. We ask: does the model, when parameterized to match salient characteristics of plant-level data (Colombia and South Korea), predict large aggregate TFP...

We study the gains from trade in a model with endogenously variable markups. We show that the pro-competitive gains from trade are large if the economy is characterized by (i) extensive misallocation, i.e., large inefficiencies associated with markups, and (ii) a weak pattern of cross-country...

We evaluate and partially challenge the ‘household leverage' view of the Great Recession. In the data, employment and consumption declined more in states where household debt declined more. We study a model where liquidity constraints amplify the response of consumption and employment to...

During the Great Recession, regions of the United States that experienced the largest declines in household debt also experienced the largest drops in consumption, employment, and wages. Employment declines were larger in the nontradable sector and for firms that were facing the worst credit...