The social rate of discount is a crucial driver of the social cost of carbon (SCC), i.e. the expected present discounted value of marginal damages resulting from emitting one ton of carbon today. Policy makers should set carbon prices to the SCC using a carbon tax or a competitive permits...

The appraisal of public investments is subject to formal guidelines which often require input prices, such as forecasted energy prices. Using Danish guidelines as a case study, we explore the discounting assumptions in these input prices and find rates ranging from 2.97% to 17.5%, markedly...

It is well recognised that the issue of the social rate of discount applies only to the gains from public investment that accrues to the public sector. When it comes to measurement, however, there is a problem: public investment in infrastructure and the like do not usually yield direct...

A formula is derived for the social cost of carbon (SCC) that takes account of intragenerational income inequality and its evolution with economic growth. The social discount rate (SDR) should be adjusted to account for intragenerational and intergenerational inequality aversion and for risk...

Under conditions of risk it makes a difference whether the discount rate is determined as an expected present or as an expected future value. This difference which is dubbed as the Weitzman-Gollier puzzle has stimulated an intensive discussion which, however, is somewhat confusing. In this paper...

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...

Uncertainty has an almost negligible impact on project value in the economic standard model. I show that a comprehensive evaluation of uncertainty and uncertainty attitude changes this picture fundamentally. The analysis relies on the discount rate, which is the crucial determinant in balancing...

Weitzman's Dismal Theorem has that the expected net present value of a stock problem with a stochastic growth rate with unknown variance is unbounded. Cost-benefit analysis can therefore not be applied to greenhouse gas emission control. We use the Generalized Central Limit Theorem to show that...

When deciding on the social desirability of public investment, the cost of a project is sometimes adjusted by a factor known as the Marginal Cost of Public Funds (MCPF) which captures the cost of raising public funds through distortionary taxation. However, there is no scholarly consensus on...

Should public assets such as infrastructure, education, and the environment earn the same return as private investments? The long-term nature of public investments provides commitment to current preferences, which justifies lower than private returns for time-inconsistent decision markers. An...