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...

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...

Discounting future costs and benefits is a crucial yet contentious practice in the appraisal of long-term public projects with environmental consequences. The standard approach typically neglects that ecosystem services are not easily substitutable with manufactured goods and often exhibit...

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...

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...

The Ramsey rule for the consumption rate of discount assumes a transfer of money of a (representative) agent at one point in time to the same agent at another point in time. Climate policy (implicitly) transfers money not just over time but also between agents. I propose three alternative...

This paper explores how a principal with time-inconsistent preferences invests optimally in technology or capital. If the current principal prefers her future self to save more, she can increase current investments complementary to future savings and decrease investments in the strategic...

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...

We propose and axiomatize probability adjusted rank-discounted critical-level generalized utilitarianism (PARDCLU). We thus generalize rank-discounted utilitarianism (RDU) (proposed by Zuber and Asheim, 2012) to variable population and risky situations and thereby take important steps towards...

We show how optimal saving in a two-period model is affected when prudence and risk aversion 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...