Distinguishing the two rates helps resolve arguments as to whether the choice of discount rate should be based on ethical considerations or empirical information (such as market interest rates), and about whether the discount rate should serve a prescriptive or descriptive role. Separating out...

Donald Trump's election and his nomination of Scott Pruitt, a climate skeptic, to lead the Environmental Protection Agency drastically downshifted expectations on US climate-change policy. We study firms' stock-price reactions and institutional investors' portfolio adjustments after these...

Climate change remains one of the major international environmental challenges facing nations. Up to now, nations have to date adopted minimal policies to slow climate change. Moreover, there has been no major improvement in emissions trends as of the latest data. The current study uses the...

This paper develops a theoretical foundation for the social cost of carbon (SCC). The model highlights the source of debate over whether countries should use the global or domestic SCC for regulatory impact analysis. I identify conditions under which a country's decision to internalize the...

In the debate about the correct discount rate to use in evaluating policy with regard to climate change, which covers the entire world and extends for centuries, the conditions for deploying benefit-cost analysis are often overlooked. Where (a) income distributional effects of policies are large...

We study optimal climate policy when climate tipping points and solar geoengineering are present. Solar geoengineering reduces temperatures without reducing greenhouse gas emissions. Climate tipping points are irreversible and uncertain events that cause large damages. We analyze three different...

The initial hope for climate science was that an improved understanding of what the future might bring would lead to appropriate public policies and effective international climate agreements. Even if that hope is not realized, as now seems likely, scientific advances leading to a more refined...

We consider the socially optimal use of solar geoengineering to manage climate change. Solar geoengineering can reduce damages from atmospheric greenhouse gas concentrations, potentially more cheaply than reducing emissions. If so, optimal policy includes less abatement than recommended by...

Extremely low discount rates play a central role in the Stern Review's evaluation of environmental protection, and this assumption has been criticized by many economists. The Review also stresses that great uncertainty is a critical element for optimal environmental policies. An appropriate...

Country incentives to participate in cooperative arrangements which either fully or partially internalize climate change externalities from carbon emissions involve critical asymmetries. Small countries trade off own country costs of carbon mitigation actions against their own benefits from...