It is not immediately clear how to discount distant-future events, like climate change, when the distant-future discount rate itself is uncertain. The so-called "Weitzman-Gollier puzzle" is the fact that two seemingly symmetric and equally plausible ways of dealing with uncertain future discount...

The usually assumed two categories of costs involved in climate change policy analysis, namely abatement and damage costs, hide the presence of a third category, namely adaptation costs. This dodges the determination of an appropriate level for them. Including adaptation costs explicitly in the...