Policymakers concerned about rapid swings in commodity prices seek economic guidance about causal factors and future trends, but standard models—based on Harold Hotelling’s classic 1931 theory—are unable to explain actual data on price variability for a wide range of commodities. In this...

Why is inflation persistently high in some periods and low in others? The reason may be the absence of commitment in monetary policy. In a standard model, absence of commitment leads to multiple equilibria, or expectation traps, even without trigger strategies. In these traps, expectations of...

We describe a class of monetary economies that generate persistent episodes of high and low inflation. In this class of economies, variations in expectations can lead private agents to take actions which then make it optimal for the monetary authority to validate those expectations. We think...

Why is inflation persistently high in some periods and low in others? The reason may be absence of commitment in monetary policy. In a standard model, absence of commitment leads to multiple equilibria, or expectation traps, even without trigger strategies. In these traps, expectations of high...

This paper studies the quantitative properties of fiscal and monetary policy in business cycle models. In terms of fiscal policy, optimal labor tax rates are virtually constant and optimal capital income tax rates are close to zero on average. In terms of monetary policy, the Friedman rule is...

This study analyzes two monetary economies, a cash-credit good model and a limited-participation model. In these models, monetary policy is made by a benevolent policymaker who cannot commit to future policies. The study defines and analyzes Markov equilibrium in these economies and shows that...

Why is inflation persistently high in some periods and low in others? The reason may be the absence of commitment in monetary policy. In a standard model, absence of commitment leads to multiple equilibria, or "expectation traps", even without trigger strategies. In these traps, expectations of...