I study a model of multiple currencies in which sellers can choose the currency they will accept. I provide conditions that are necessary and sufficient to avoid indeterminacy of the exchange rate. Under these assumptions, all stable equilibria have the property that all sellers in the same...

We consider an environment in which participants make payments over a network and can invest in a technology that reduces the marginal cost of using the network. A network effect results in multiple equilibria; either all agents invest and usage of the network is high or no agents invest and...

We study several popular monetary models which generate a nondegenerate stationary distribution of money holdings. Across these environments, our principal finding is as follows: a monetary policy that sets long run nominal interest rates to zero (the Friedman rule) does not typically maximize...

It is a puzzling fact that many central banks choose to lend intra-day funds at an interest rate of zero (or very close to zero), while the interest rate on overnight funds is much higher. I build a general equilibrium model where intra-day liquidity is needed because it is costly to make...

This paper establishes the existence of equilibria for environments in which outside money is issued competitively. Such equilibria are typically believed not to exist because of a classic overissue problem: if money is valued in equilibrium, an issuer produces money until its value is driven to...

Recent papers suggest that when intermediation is analyzed seriously, the Friedman rule does not maximize social welfare in overlapping generations model in which money is valued because of spatial separation and limited communication. These papers emphasize a trade-off between productive...

We propose a theory to explain the choice between nominal and indexed labor contracts. We find that contracts should be indexed if prices are difficult to forecast and nominal otherwise. Our analysis is based on a principal-agent model developed by Jovanovic and Ueda (1997) in which...

In many models of financial intermediation, markets reduce welfare because they limit the amount of risk-sharing intermediaries can offer. In this paper we study a model in which markets also promote investment in a productive technology. A trade-off between risk sharing and growth arises...

Bagehot (1873) states that in order to prevent bank panics a central bank should provide liquidity to the market at a "very high rate of interest". This seems to be in sharp contrast with the policy adopted by the Federal Reserve after September 11 when, for a few days, the Federal Funds Rate...