Colonial Americans complained that gold and silver coins (specie) were chronically scarce. These coins could be acquired only through importation. Given unrestricted trade in specie, market arbitrage should have eliminated chronic scarcity. A model of efficient barter and local inside money is...

In recent decades, advanced economies have experienced low and stable inflation and long periods of liquidity trap. We construct an alternative business-cycle model capturing these two features by adding two assumptions to a money-in-the-utility-function model: the labor market is subject to...

When the zero lower bound on nominal interest rates binds, monetary policy cannot provide appropriate stimulus. We show that in the standard New Keynesian model, tax policy can deliver such stimulus at no cost and in a time-consistent manner. There is no need to use inefficient policies such as...

We analyze a new class of equilibria that emerges when a central bank conducts monetary policy by setting an interest rate (as an arbitrary function of its available information) and letting the private sector set the quantity traded. These equilibria involve a run on the central bank's interest...

The federal funds rate has been at the zero lower bound for over four years, since December 2008. According to standard macroeconomic models, this should have greatly reduced the effectiveness of monetary policy and increased the efficacy of fiscal policy. However, these models also imply that...

We analyze the optimal Taylor rule in a standard New Keynesian model. If the central bank can observe the output gap and the inflation rate without error, then it is typically optimal to respond infinitely strongly to observed deviations from the central bank's targets. If it observes inflation...