We propose a simple method to help researchers develop quantitative models of economic fluctuations. The method rests on the insight that many models are equivalent to a prototype growth model with time-varying wedges which resemble productivity, labor and investment taxes, and government...

The New-Keynesian aggregate supply derives from micro-foundations an inflation-dynamics model very much like the tradition in the monetary literature. Inflation is primarily affected by: (i) economic slack; (ii) expectations; (iii) supply shocks; and (iv) inflation persistence. This paper...

This paper develops a model of unemployment fluctuations. The model keeps the architecture of the general-disequilibrium model of Barro and Grossman (1971) but takes a matching approach to the labor and product markets instead of a disequilibrium approach. On the product and labor markets, both...

This paper develops a dynamic model of trade and growth that we use to study how openness affects economic growth. In our model, heterogeneous firms choose to either produce with their existing technology or search within the domestic economy to adopt a better technology. These choices determine...

In this paper we provide a model of the macroeconomic consequences of a shortage of safe assets. In particular, we discuss the emergence of a deflationary safety trap equilibrium which is an acute form of a liquidity trap. In this context, issuing public debt, swapping private risky assets for...

We argue that the vast bulk of movements in aggregate real economic activity during the Great Recession were due to financial frictions interacting with the zero lower bound. We reach this conclusion looking through the lens of a New Keynesian model in which firms face moderate degrees of price...

How does the output response to a change in government spending vary over the business cycle? What are the welfare effects of spending shocks? This paper studies the state-dependence of the output and welfare effects of shocks to government purchases in a DSGE model with real and nominal...

We propose a network model of firm volatility in which the customers' growth rate shocks influence the growth rates of their suppliers, larger suppliers have more customers, and the strength of a customer-supplier link depends on the size of the customer firm. Even though all shocks are i.i.d.,...

Extremely low discount rates play a central role in the Stern Review's evaluation of environmental protection, and this assumption has been criticized by many economists. The Review also stresses that great uncertainty is a critical element for optimal environmental policies. An appropriate...

This paper provides new evidence in support of the idea that bouts of optimism and pessimism drive much of US business cycles. In particular, we begin by using sign-restriction based identification schemes to isolate innovations in optimism or pessimism and we document the extent to which such...