In this paper, we consider a dynamic economy in which the agents in the economy are privately informed about their skills, which evolve stochastically over time in an arbitrary fashion. We consider an asset pricing equilibrium in which equilibrium quantities are constrained Pareto optimal Under...

Over the past thirty years, a great deal of business cycle research has been based on purely real models that abstract from the presence of nominal rigidities, and so (at least implicitly) assume that the Phillips curve is vertical. In this paper, I show that such models are fragile, in the...

In this article, I consider environments in which all shocks have finite support and any transfer of resources is ex post voluntary. Consider an allocation that is achievable when potential trading partners know each others' histories. The one-money theorem says that the allocation is achievable...

In this article, I examine the current state of knowledge about optimal monetary policy. I distinguish between two literatures, basic and applied. The basic literature is explicit about the frictions that generate a positive value for money and make it socially beneficial. The applied literature...