The generation and implementation of ideas, or knowledge, is crucial for economic performance. We study this process in a model of endogenous growth with frictions. Productivity increases with knowledge, which advances via innovation, and with the exchange of ideas from those who generate them...

Why do some sellers set nominal prices that apparently do not respond to changes in the aggregate price level? In many models, prices are sticky by assumption; here it is a result. We use search theory, with two consequences: prices are set in dollars, since money is the medium of exchange; and...

We study models of credit with limited commitment, which implies endogenous borrowing constraints. We show that there are multiple stationary equilibria, as well as nonstationary equilibria, including some that display deterministic cyclic and chaotic dynamics. There are also stochastic...

We study bilateral exchange, both direct trade and indirect trade that happens through chains of intermediaries or middlemen. We develop a model of this activity and present applications. This illustrates how, and how many, intermediaries get involved, and how the terms of trade are determined....

Many applications of search theory in monetary economics use the Shi-Trejos-Wright model, hereafter STW, while applications in finance use Duffie-Gârleanu-Pederson, hereafter DGP. These approaches have much in common, and both claim to be about liquidity, but the models also differ in a...

This essay articulates the principles and practices of New Monetarism, our label for a recent body of work on money, banking, payments, and asset markets. We first discuss methodological issues distinguishing our approach from others: New Monetarism has something in common with Old Monetarism,...

The purpose of this paper is to discuss some of the models used in New Monetarist Economics, which is our label for a body of recent work on money, banking, payments systems, asset markets, and related topics. A key principle in New Monetarism is that solid microfoundations are critical for...

Dynamic general equilibrium models that include explicit household production sectors provide a useful framework within which to analyze a variety of macroeconomic issues. However, some implications of these models depend critically on parameters, including the elasticity of substitution between...

We analyze economies with indivisible commodities. There are two reasons for doing so. First, we extend and provide new insights into sunspot equilibrium theory. Finite competitive economies with perfect markets and convex consumption sets do not allow sunspot equilibria; these same economies...

We document and attempt to explain the observation that automobile insurance premiums vary dramatically across local markets. We argue high premiums can be attributed to the large numbers of uninsured motorists in some cities, while at the same time, the uninsured motorists can be attributed to...