The epidemiological literature suggests that virus transmission occurs only when individuals are in relatively close contact. We show that if society can control the extent to which economic agents are exposed to the virus and agents can commit to contracts, virus externalities are local, and...

We develop a simple dynamic economic model of epidemic transmission designed to be consistent with widely used SIR biological models of the transmission of epidemics, while incorporating economic benefits and costs as well. Our main finding is that targeted testing and isolation policies deliver...

We document regularities in the distribution of relative incomes and patterns of investment in countries and over time. We develop a quantitative version of the neoclassical growth model with a broad measure of capital in which investment decisions are affected by distortions. These distortions...

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...

Why is it that inflation is persistently high in some periods and persistently low in other periods? We argue that lack of commitment in monetary policy may bear a large part of the blame. We show that, in a standard equilibrium model, absence of commitment leads to multiple equilibria, or...

Chamley and Judd argued that optimal taxation dictates zero long-run tax rates on capital income, but Straub and Werning found that tax rates may be positive even in the steady state. These models feature a "period-zero problem" in the underlying Ramsey formulation, which omits past commitments...

The data show large and persistent deviations of real exchange rates from purchasing power parity. Recent work has shown that to a large extent these movements are driven by deviations from the law of one price for traded goods. In the data, real and nominal exchange rates are about 6 times as...