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...

Climate is a persistent asset, bar none: changes in climate-related stocks have consequences spanning over centuries or possibly millennia to the future. To reconcile the discounting of such far-distant impacts and realism of the shorter-term decisions, we consider hyperbolic time-preferences in...

The paper derives the optimal carbon tax in closed-form from an integrated assessment of climate change. The formula shows how carbon, temperature, and economic dynamics quantify the optimal mitigation effort. The model's descriptive power is comparable to numeric models used in policy advising....

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...

This paper reviews recent research on the aggregation of heterogeneous time preferences. Main results are illustrated in simple Ramsey models with two or three agents who differ in their discount factors. We employ an intertemporal view on these models and argue that preferences of a decision...

The paper develops an axiomatic framework for rational decision making. The von Neumann-Morgenstern axioms give rise to a richer risk attitude than that captured in the standard discounted expected utility model. I derive three models that permit a more comprehensive risk evaluation. These...

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 paper reexamines the welfare economics of intergenerational risk. Risk and its resolution over time are modeled as a decision tree: in each period, the consumption of the current one-period living generation is to be traded-off against uncertain benefits of future generations; as time...

In this paper we analyze a large sample of individual responses to six lottery questions. We derive a simultaneous estimate of risk aversion and the time preference discount rate per individual. This can be done because the consumption of a large prize is smoothed over a larger time period. It...

People’s value for their own time is a key input in evaluating public policies: evaluations should account for time taken away from work or leisure as a result of policy. Using rich choice data collected from farming households in western Kenya, we show that households exhibit non-transitive...