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

The desirability of fiscal constraints in monetary unions depends critically on whether the monetary authority can commit to follow its policies. If it can commit, then debt constraints can only impose costs. If it cannot commit, then fiscal policy has a free-rider problem, and debt constraints...

The central puzzle in international business cycles is that real exchange rates are volatile and persistent. The most popular story for real exchange rate fluctuations is that they are generated by monetary shocks interacting with sticky goods prices. We quantify this story and find that it can...

We develop a model in which, in order to provide managerial incentives, it is optimal to have costly bankruptcy. If benevolent governments can commit to their policies, it is optimal not to interfere with private contracts. Such policies are time inconsistent in the sense that, without...

The desirability of fiscal constraints in monetary unions depends critically on whether the monetary authority can commit to follow its policies. If it can commit, then debt constraints can only impose costs. If it cannot commit, then fiscal policy has a free-rider problem, and debt constraints...

The central puzzle in international business cycles is that fluctuations in real exchange rates are volatile and persistent. We quantity the popular story for real exchange rate fluctuations: they are generated by monetary shocks interacting with sticky goods prices. If prices are held fixed for...

We propose a definition of time consistent policy for infinite horizon economies with competitive private agents. Allocations and policies are defined as functions of the history of past policies. A sustainable equilibrium is a sequence of history-contingent policies and allocations that satisfy...