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...

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...

We show how optimal saving in a two-period model is affected when prudence and riskaversion of the underlying utility function change. Increasing prudence alone will induce higher savings only if, for certain combinations of the interest rate and the pure time discount rate, there is...

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...

World income grows fast without verifiable climate-change impacts on the economy. The growth spell can end if climate impacts turn real but this can take decades to learn. We develop a tractable stochastic climate-economy model with a hidden-state impact process to evaluate the contributions of...

Should public assets such as infrastructure, education, and the environment earn the same return as private investments? We consider if time-inconsistent decision-makers can gain from institutions that enforce cost-benefit rules on large projects that influence the economy as a whole. Long-term...

There are many reasons to suspect that benefit-cost analysis applied to environmental policies will result in policy decisions that will reject those environmental policies. The important question, of course, is whether those rejections are based on proper science. The present paper explores...

That climate policies are costly is evident and therefore often creates major fears. But the alternative (no action) also has a cost. Mitigation costs and damages incurred depend on what the climate policies are; moreover, they are substitutes. This brings climate policies naturally in the realm...

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...

Recent theoretical work in the economics of climate change has suggested that climate policy is highly sensitive to ‘fat-tailed’ risks of catastrophic outcomes (Weitzman, 2009b). Such risks are suggested to be an inevitable consequence of scientific uncertainty about the effects of increased...