The social cost of greenhouse gases is important in many regulatory impact analyses. However, calculations of the social cost of greenhouse gases are highly complex and periodically revisited. We offer seven recommendations to improve current estimates. These include recommendations to use both country-level and global measures of the social cost of greenhouse gases, to use country-specific values for monetizing climate damages, to represent uncertainties by reporting distributions instead of using only central values, and to conduct a temporal distributional analysis that shows the magnitudes of climate damages across generations. We also provide recommendations for the discount rates that should be used when estimating the social cost of greenhouse gases, and the appropriate discount rates for regulatory impact analyses that include the social cost of greenhouse gases.

Time preferences may explain public opinion about a wide range of long-term policy problems with costs and benefits realized in the distant future. However, mass publics may discount these costs and benefits because they are later or because they are more uncertain. Standard methods to elicit individual-level time preferences tend to conflate risk and time attitudes and are susceptible to social desirability bias. A potential solution relies on a costly lab-experimental method, convex time budgets (CTB). We present and experimentally validate an affordable version of this approach for implementation in mass surveys. We find that the theoretically preferred CTB patience measure predicts attitudes toward a local, delayed investment problem but fails to predict support for more complex, future-oriented policies.

The objective of this paper is to measure and compare the subjective time discounting of professional athletes and non-athletes. By using a questionnaire, we found higher subjective discounting for professional athletes than for non-athletes. We also found that the professional athletes’ win-orientation positively affected their present preferences. On the other hand, professional athletes’ play- orientation, which reflects their attitude towards the game itself, negatively affected their present preferences. No such effects were found in non-athletes. We argue that the “win-at-all-costs” competitive approach that leads athletes to sacrifice everything in order to win may cause (or reflect) their higher preference for the present.

In two studies, time preferences for financial gains and losses at delays of up to 50 years were elicited using three different methods: matching, fixed-sequence choice titration, and a dynamic “staircase” choice method. Matching was found to create fewer demand characteristics and to produce better fits with the hyperbolic model of discounting. The choice-based measures better predicted real-world outcomes such as smoking and payment of credit card debt. No consistent advantages were found for the dynamic staircase method over fixed-sequence titration.

To study intertemporal choices, researchers typically instruct subjects to choose between smaller and sooner (SS) and larger and later (LL) rewards (e.g., gaining CNY 210 in a week vs. gaining CNY 250 in five weeks). People generally tend to discount steeply and prefer SS to LL rewards in such situations. Jiang, Hu and Zhu (2014) recently showed that adding upfront losses or gains to both SS and LL rewards can reduce people’s discounting, and they provided several possible accounts for this effect, including the salience account and the time scale hypothesis. In the current paper, based on the upfront money effect found in Jiang et al. (2014), we further showed that the effect of discounting decreasing could be extended to adding dated-money between SS and LL rewards and after LL rewards. The results helped us exclude both the time scale hypothesis and another possible explanation: preference for improvement. We hypothesized that all the current findings (recorded in this paper and in Jiang et al.) could be accommodated well using the salience account.

The goal of natural resource damage assessment (NRDA) is to compensate the public for losses to natural resources from past or ongoing hazardous releases, including losses that may persist into the future. Compensation is delivered in the form of restoration projects. Resolving NRDA liability requires balancing losses and restoration benefits over multiple decades and converting them into a present value for calculating appropriate damages. For the past two decades, NRDA practitioners have used a real discount rate of 3 % to convert losses and benefits to a present value equivalent. That rate was based, in part, on real historical yields on risk-free debt (e.g., the real rate of return on 3-month Treasury bills). Declining interest rates on risk-free debt in recent years has led to suggestions to reexamine the historical consensus discount rate. This paper reviews two alternative conceptual paradigms for selecting a discount rate in NRDA cases: the social rate of time preference and discount rates for tort cases. We summarize historical data for empirically implementing the two paradigms and discuss the ramifications of the different options. Based on our review, we suggest maintaining the 3 % consensus as a practical solution to a range of empirical candidates within the two conceptual paradigms.

Uncertain future risks pose cognitive and analytical challenges to household decision makers. Risks with uncertain probabilities, coupled with potentially severe outcomes pose problems for decision-making and are prone to overreactions. Imprecision in risk estimates generates behavioral distortions such as ambiguity aversion. This article presents new empirical results indicating household overvaluations of uncertain threats posed by several drinking water risks: traces of prescription drugs in drinking water, plastic water bottles with bisphenol-A, and the weed killer atrazine in drinking water. Negative reactions reflect responses to ambiguous risks, but policies driven by these concerns may misallocate regulatory resources due to risk conservatism and “no-regrets” responses.

We study the social discount rate, taking into account inequality within generations, that is, across countries or individuals. We show that if inequality decreases over time, the social discount rate should be lower than the one obtained by the standard Ramsey rule under certain but reasonable conditions. Applied to the global discount rate and due to the projected convergence across countries, this implies that the inequality adjusted discount rate should be about twice as high as the standard Ramsey rule predicts. For individual countries on the other hand, where inequality tends to increase over time, the effect goes in the other direction. For the United States for instance, this inequality effect leads to a reduction of the social discount rate by about 0.5 to 1 percentage points. We also present an analytical formula for the social discount rate allowing us to disentangle inequality, risk, and intertemporal fluctuation aversion.

In this paper, I explore in an overlapping generations framework, a mechanism motivating a neurobiological poverty trap. Poverty causes stress and depression in individuals susceptible to depression. Poor and depressed individuals discount the future at a higher rate and invest less in the human capital of their children than mentally healthy or rich individuals. This gene–environment interaction generates a vicious cycle in which poor individuals inherit not only susceptibility to depression, but also stress and poverty. I show that a successful one-time intervention has the power to permanently eliminate the neurobiological poverty trap.

This study compares equivalent annual rents for two alternative land uses in a region where farming and timber plantations coexist. The comparison is motivated by the possibility that rising timber prices may stimulate timber processors to compete for farmland. Prices, costs, and market rents are assumed to first follow existing trends and then to reach steady state values. Market rents are projected and capitalized for agriculture. Internal soil rents are capitalized for timber. The results show timber to have a comparative advantage on high fertility sites and suggest that timber might become a competitive land use at the intensive margin of the region's farmland base.

Understanding money requires that we first grasp what makes money so significant—so valuable—to us. The article thus examines the sociology outlined by Geoffrey Ingham and criticises its ontology of money as a measure of value underpinned by state authority. By contrast, it argues that money ought to be primarily intended as value in itself. Accordingly, money’s most specific attribute is none of its canonical functions but rather purchasing power: the power not to pay, or else the power to buy time. The latter is not the mere product of state (fiscal) agency, but is entangled from the start with the production of liquidity and the construction of speculative markets for debt. Thus the paper emphasises the importance of concrete bank discounting vis-à-vis abstract accounting in concrete processes of monetisation, and shows how modern money, far from cancelling debts, is historically constructed within liquid financial relations so as to “buy time” and systematically procrastinate the final “rendering of accounts” for debtors. As a result, money cannot exist without the simultaneous existence of a debt that it will never discharge.