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...

Herd behavior is argued by many to be present in many markets. Existing models of such behavior have been subjected to two apparently devastating critiques. The continuous investment critique is that in the basic model herds disappear if simple zero-one investment decisions are replaced by the...

Here we reply to Robert Solow’s comment (forthcoming) on our work (Chari and Kehoe (2007)).

The optimal choice of a monetary policy instrument depends on how tight and transparent the available instruments are and on whether policymakers can commit to future policies. Tightness is always desirable; transparency is only if policymakers cannot commit. Interest rates, which can be made...

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...

The main substantive finding of the recent structural vector autoregression literature with a differenced specification of hours (DSVAR) is that technology shocks lead to a fall in hours. Researchers have used these results to argue that business cycle models in which technology shocks lead to a...

In the 1970s macroeconomists often disagreed bitterly. Macroeconomists have now largely converged on method, model design, and macroeconomic policy advice. The disagreements that remain all stem from the practical implementation of the methodology. Some macroeconomists think that New Keynesian...

We make two comparisons relevant for the business cycle accounting approach. We show that in theory representing the investment wedge as a tax on investment is equivalent to representing this wedge as a tax on capital income as long as the probability distributions over this wedge in the two...

In standard approaches to monetary policy, interest rate rules often lead to indeterminacy. Sophisticated policies, which depend on the history of private actions and can differ on and off the equilibrium path, can eliminate indeterminacy and uniquely implement any desired competitive...