Economic evaluation of climate policy is notoriously dependent on assumptions about time and risk preferences, since reducing greenhouse gas emissions today has a highly uncertain payoff, far into the future. These assumptions have always been much debated. Rather than occupy a position in this...

This paper describes conditions under which one investment project dominates a second project in terms of net present value, irrespective of the choice of the discount rate. The resulting partial ordering of projects has certain similarities to stochastic dominance. However, the structure of the...