Many of the facts about the extensive margin of trade—which firms export, and how many products are sent to how many destinations—are consistent with a surprisingly large class of trade models because of the sparse nature of trade data. We propose a statistical model to account for sparsity,...

Cross-country income gaps are large in the data. Can observed investment prices account for these gaps? Our model adds an extensive margin to the neoclassical growth model by allowing for entry of firms. When combined with a “returns to variety” effect, our model provides an amplification...

This paper characterizes the time-consistency properties of the set of Pareto efficient (or second best) fiscal policies, in a two-class, stochastic economy similar to that in Judd (1985). The key finding is that the continuation of any Pareto efficient policy is always Pareto efficient. Hence,...

This paper studies the long run properties of intertemporal distortions in a broad class of second best economies. Our unified framework encompasses and extends many well known models, such as variants of the Ramsey taxation model with aggregate or idiosyncratic risk, and economies with...