We study a dynamic stochastic general equilibrium model where agents are concerned about model uncertainty regarding climate change. An externality from greenhouse gas emissions adversely affects the economys capital stock. We assume that the mapping from climate change to damages is subject to...

Emissions trading mechanisms have been proposed, and in some cases implemented, as a tool to reduce pollution. We explore the similarities between emission-trading mechanisms and monetary mechanisms. Both attempt to implement desirable allocations under various frictions, including risk and...

We study innovation in a dynamic stochastic discrete-time duopoly with endogenous horizontal differentiation. Innovation takes the form of a quality ladder; horizontal differentiation is Hotelling competition. We compute Markov-perfect equilibria and study the effects on long-run innovation of...

Within the framework of Diamond-Dybvig (1983), the optimal (run free) outcome is shown to be the unique forward induction equilibrium. In a version of the model that posits Bertrand competition among banks, there are sequential equilibria that imply positive profits. However, the zero-profit...

We introduce an element of centralization in a random matching model of money that allows for private liabilities to circulate as media of exchange. Some agents, which we identify as banks, are endowed with the technology to issue notes and to record-keep reserves with a central clearinghouse,...

Under take-it-or-leave-it offers, dynamic equilibria in the discrete time random matching model of money are a "translation" of dynamic equilibria in the standard overlapping generations model. This formalizes earlier conjectures about the equivalence of dynamic behavior in the two models and...

We study the emergence and coexistence of monetary and credit transactions in a model where exchange is decentralized. Agents belong to different villages which are informationally separated. The frequency of meetings between any two different villages decreases as their respective geographic...