The authors use the framework of random matching games and develop a two-country model of the world economy in which two national currencies compete and may be circulated as media of exchange. There are multiple equilibria, which differ in the areas of circulation of the two currencies. In one...

We develop a model in which innovations in an economy's growth potential are an important driving force of the business cycle. The framework shares the emphasis of the recent "new shock" literature on revisions of beliefs about the future as a source of fluctuations, but differs by tieing these...