What is the best way to incorporate a risk premium into the discount rate schedule for a real investment project with uncertain payoffs? The standard CAPM formula suggests a beta-weighted average of the return on a safe investment and the mean return on an economy-wide representative risky...

Suppose that there is a probability density function for how bad things might get, but that the overall rate at which this probability density function slims down to approach zero in the tail is uncertain. The paper shows how a basic precautionary principle of tail fattening could then apply....

The long term discount rate is critically dependent upon projections of future growth rates that are fuzzier in proportion to the remoteness of the time horizon. This paper models such increasing fuzziness as an evolving hidden-state stochastic process. The underlying trend growth rate is an...

Climate change is a global "free rider" problem because significant abatement of greenhouse gases is an expensive public good requiring international cooperation to apportion compliance among states. But it is also a global "free driver" problem because geoengineering the stratosphere with...

Using climate change as a prototype motivating example, this paper analyzes the implications of structural uncertainty for the economics of low-probability high-impact catastrophes. The paper shows that having an uncertain multiplicative parameter, which scales or amplifies exogenous shocks and...

Linkage of cap-and-trade systems is typically advocated by economists on a general analogy with the beneficial linking of free-trade areas and on the specific grounds that linkage will ensure cost effectiveness among the linked jurisdictions. An appropriate and widely accepted specification for...

This paper postulates the conceptually useful allegory of a futuristic “World Climate Assembly” (WCA) that votes for a single worldwide price on carbon emissions via the basic democratic principle of one-person one-vote majority rule. If this WCA framework can be accepted in the first place,...

It is difficult to resolve the global warming free-rider externality problem by negotiating many different quantity targets. By contrast, negotiating a single internationally-binding minimum carbon price (the proceeds from which are domestically retained) counters self-interest by incentivizing...

The possibility of intertemporal banking and borrowing of tradeable permits is often viewed as tilting the various policy debates about optimal pollution control instruments toward favoring such time-flexible quantities. The present paper shows that this view is misleading, at least for the...

Using only information based on current directly-observable market behavior, the paper shows how to make rigorous dynamic welfare comparisons among economies or economic situations having arbitrarily-different endowments and technologies, but sharing a common dynamic preference ordering. The...