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...

Recent empirical work on financial crises documents that crises tend to occur when macroeconomic fundamentals are weak; but even after conditioning on an exhaustive list of fundamentals, a sizable random component to crises and associated capital flows remains. We develop a model of herd...

Macroeconomists have largely converged on method, model design, reduced-form shocks, and principles of policy advice. Our main disagreements today are about implementing the methodology. Some think New Keynesian models are ready to be used for quarter-to-quarter quantitative policy advice. We do...

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 that resemble productivity, labor and investment taxes, and government...

Over the last three decades, macroeconomic theory and the practice of macroeconomics by economists have changed significantly -- for the better. Macroeconomics is now firmly grounded in the principles of economic theory. We focus on the role of economic theory in shaping policy. Over the last...