We study a non-parametric class of neoclassical trade models with global production networks. We characterize their properties in terms of sufficient statistics useful for growth and welfare accounting as well as for counterfactuals. We establish a formal duality between open and closed...

Aggregate production functions are reduced-form relationships that emerge endogenously from input-output interactions between heterogeneous producers and factors in general equilibrium. We provide a general methodology for analyzing such aggregate production functions by deriving their first-...

How does an increase in the size of the market due to fertility, immigration, or trade integration, affect welfare and real GDP? We study this question using a model with heterogeneous firms, fixed costs, and monopolistic competition. We decompose the change in welfare into changes in technical...

A tension between entry and rents lies at the core of a general theory of aggregation with scale effects. This paper characterizes the responses of macro aggregates to micro shocks in disaggregated economies with general forms of entry, internal or external returns to scale, input-output...

We study supply and demand shocks in a general disaggregated model with multiple sectors, multiple factors, input-output linkages, downward nominal wage rigidities, credit-constraints, and a zero lower bound. We use the model to understand how the Covid-19 crisis, an omnibus of supply and demand...

We use a five-age epidemiological model, combined with 66-sector economic accounting, to address a variety of questions concerning the economic reopening. We calibrate/estimate the model using contact survey data and data on weekly historical individual actions and non-pharmaceutical...

We study the effects of negative supply shocks and shocks to the composition of final demand on aggregate output in a disaggregated neoclassical model with multiple sectors, factors, and input-output linkages. We show how nonlinearities associated with complementarities in consumption and...

We propose a supply-side channel for the transmission of monetary policy. We study an economy with heterogeneous firms, sticky prices, and endogenous markups. We show that if, as is consistent with the empirical evidence, bigger firms have higher markups and lower pass-throughs than smaller...

The Covid-19 crisis is an unusual and seemingly all-encompassing economic shock. On the one hand, it was unquestionably a negative demand shock that, for fixed prices and incomes, reduced household spending. On the other hand, it was also unquestionably a negative supply shock that reduced...

We investigate the effects of input variety creation and destruction on both micro- and macroeconomic outcomes using detailed data from Belgium. We estimate that marginal costs rise by 0.6% for every 1% of suppliers lost. We show that this elasticity measures the area under the input demand...