The primary motivation behind quantitative modeling in international trade and many other fields is to shed light on the economic consequences of policy changes. To help assess and potentially strengthen the credibility of such quantitative predictions we introduce an IV-based goodness-of-fit...

This paper develops an elementary theory of global supply chains. We consider a world economy with an arbitrary number of countries, one factor of production, a continuum of intermediate goods, and one final good. Production of the final good is sequential and subject to mistakes. In the unique...

We develop a model of investment with financial constraints and use it to investigate the relation between investment and Tobin's q. Afirm is financed partly by insiders, who control its assets, and partly by outside investors. When their wealth is scarce, insiders earn a rate of return higher...

We explore empirically models of aggregate fluctuations with two basic ingredients: agents form anticipations about the future based on noisy sources of information and these anticipations affect spending and output in the short run. Our objective is to separate fluctuations due to actual...

The arrival of new, unfamiliar, investment opportunities is often associated with exuberant movements in asset prices and real economic activity. During these episodes of high uncertainty, financial markets look at the real sector for signals about the profitability of the new investment...

How are optimal taxes affected by the presence of superstar phenomena at the top of the earnings distribution? To answer this question, we extend the Mirrlees model to incorporate an assignment problem in the labor market that generates superstar effects. Perhaps surprisingly, rather than...

We show that the Diamond and Mirrlees (1971) linear tax model contains the Mirrlees (1971) nonlinear tax model as a special case. In this sense, the Mirrlees model is an application of Diamond-Mirrlees. We also derive the optimal tax formula in Mirrlees from the Diamond-Mirrlees formula. In the...

We develop a multi-risk SIR model (MR-SIR) where infection, hospitalization and fatality rates vary between groups-in particular between the "young", "the middleaged" and the "old". Our MR-SIR model enables a tractable quantitative analysis of optimal policy similar to those already developed in...