In familiar models, a decrease in the friction facing mobile factors (e.g., lowering their adjustment costs) increases a coordination problem, leading to more circumstances where there are multiple equilibria. We show that a decrease in friction can decrease coordination problems if, for...

We compare the short-run and long-run effects of environmental reform and harmonization under autarky and free trade. When trade is driven by environmental distortions rather than real relative advantages, harmonization of environmental policies, even if achieved by lowering standards in one...

Low probability catastrophic climate change can have a significant influence on policy under hyperbolic discounting. We compare the set of Markov Perfect Equilibria (MPE) to the optimal policy under time-consistent commitment. For some initial levels of risk there are multiple MPE; these may...

A reform to the Kyoto Protocol that allows signatories to pay a fine instead of meeting the target level of abatement would achieve three goals. First, it would defuse one U.S. objection to the agreement: the concern that the cost of achieving the target might turn out to be extremely high....

If average costs in a nonrenewable resource industry are U-shaped, a competitive equilibrium may not be optimal and, indeed, may not exist. Although the differential equation that describes the change in the rate of extraction is the same for planner and firm, the boundary conditions obtained...

If a durable good monopolist produces at constant marginal costs and the good depreciates, there exists a family of Strong Markov Perfect Equilibrium (SMPE) with an infinitesimal period of commitment. One member of this family entails instantaneous production of the level of stock produced in a...

A constant social discount rate cannot reflect both a reasonable opportunity cost of public funds and an ethically defensible concern for generations in the distant future. We use a model of hyperbolic discounting that achieves both goals. We imbed this discounting model in a simple climate...