Discounting the Distant Future: An Experimental Investigation

We use a laboratory experiment to elicit discount rates over a 20-year time horizon using government savings bonds as a payment vehicle. When using a constant (exponential) discount rate function, we find an implied average discount rate of 4.9 %, which is much lower than has been found in previous experimental studies that used time horizons of days or months. However, we also find strong support for non-constant, declining discount rates for longer time horizons, with an extrapolated implied annual discount rate approaching 0.5 % in 100 years. There is heterogeneity in discount rates and risk preferences in that people with more optimistic beliefs about technological progress have higher discount rates. These findings contribute to the debate over the appropriate discount rate to use in comparing the long-term benefits of climate change mitigation to the more immediate costs.     

Land-use changes, forest/soil conditions and carbon sequestration dynamics: A bio-economic model at watershed level in Nepal

A dynamic bio-economic model has been used at watershed level in Nepal to analyze the land-use changes, forest and soil conditions and their resultant impacts on carbon (C) sequestration. Planning horizon of the model extends over a period of 25 years. The objective function is maximization of the sum of discounted net income flows from agriculture, livestock and forestry productions; imputed value of leisure and labour hiring out activities subject to annual constraints on land, labour and capital availability along with the fulfilment of minimum cash and consumption requirements. The seven scenarios analyzed by the model are: business as usual (BAU), reduction in population growth rate from 2 to 1.5% p.a., increased prices of major crops by 10 and 20%, reduction in emigration of active labour force from the watershed from the current rate of 20–15 and 10%, and increase in discount rate from 5 to 10%. The results indicate that reduced labour emigration rates and increase in the prices of major crops lead to expansion of cultivated area and shift from one land use to the others. Land clearing becomes more severe with decline in labour emigration rate. Up to 10% increase in the prices of agricultural crops does not have noticeable effect on total land clearing. Increase in discount rate leads to less land clearing, more biomass harvesting and higher net C sequestration as compared to the BAU scenario. Assuming a C price of 10 USD per MgC and 5% discount rate, the net present value of C sequestration for the first 25 years is estimated at 1.83 mill USD in the BAU scenario, varying from 0.16 mill USD to 2.26 mill USD, as respectively the lowest and highest values for the seven scenarios analysed. A reduction in population growth and maintenance of current rate of off-farm employment are suggested for slowing down the expansion of cultivated land area, and thereby reducing the forest/soil degradation and C emissions. This in turn would enhance the income potential from C sequestration.     

Anchoring effects in experimental discount rate elicitation

Discount rates are often elicited using incentivized or hypothetical multiple price lists. We conduct two multiple price lists according to Coller and Williams (Experimental Economics 2: 107–127, 1999) with varying ranges of larger–later payments. Participants carry out both tasks and are randomly assigned to a task order as well as to a payment or no-payment treatment. Our results indicate that the range of the first completed task anchors discount rate decisions. Participants who begin the task with the lower range of the larger–later payments stated lower discount rates than participants who start with the task containing a wider range. Paying monetary incentives does not influence the detected anchor effect.     

Interest rate assumptions and predictive accuracy of central bank forecasts

The interest rate assumptions for macroeconomic forecasts differ among central banks. Common approaches are given by the assumptions that interest rates remain constant over the forecast horizon, follow a path as expected by market participants or follow a path as expected by the central bank itself. Theoretical papers such as Svensson (The instrument-rate projection under inflation targeting: the Norwegian example. Centre for European Policy Studies Working Paper (127), 2006) and Galí (J Monet Econ 58:537–550, 2011) suggest an accuracy ranking for these forecasts, from employing central bank expectations yielding the highest forecast accuracy to conditioning on constant interest rates yielding the lowest. Yet, when investigating the predictive accuracy of the Bank of England’s and the Banco Central do Brasil’s forecasts for interest rates, inflation and output growth, we hardly find any significant differences between forecasts based on the different interest rate paths. Our results suggest that the choice of the interest rate assumption appears to be of minor relevance empirically.     

Discounting in a world of limited growth

This paper explores the consequences fordiscounting of assuming limits to growth. One of the main determinants of the discount rate is the rate of economic growth. If growth rates decline in the future then the discount rate should not be constant but also decline over time. In fact, we would then need not a single discount rate but rather a variable discount schedule. This would imply higher present values for the distant future. The paper analyses how discount rates would vary with different assumptions about the patterns of growth and the pure rate of time preference.An earlier version of this paper was presented at the conference ECOLOGICAL ECONOMICS, Stockholm, August 1992. I am grateful for valuable comments from Partha Dasgupta, Gunnar Köhlin, Karl-Göran Mäler, Mike Young and two anonymous referees.     

Infinitely repeated games in the laboratory: four perspectives on discounting and random termination

This paper compares behavior under four different implementations of infinitely repeated games in the laboratory: the standard random termination method [proposed by Roth and Murnighan (J Math Psychol 17:189–198, 1978)] and three other methods that de-couple the expected number of rounds and the discount factor. Two of these methods involve a fixed number of repetitions with payoff discounting, followed by random termination [proposed by Sabater-Grande and Georgantzis (J Econ Behav Organ 48:37–50, 2002)] or followed by a coordination game [proposed in (Andersson and Wengström in J Econ Behav Organ 81:207–219, 2012; Cooper and Kuhn in Am Econ J Microecon 6:247–278, 2014a)]. We also propose a new method—block random termination—in which subjects receive feedback about termination in blocks of rounds. We find that behavior is consistent with the presence of dynamic incentives only with methods using random termination, with the standard method generating the highest level of cooperation. Subject behavior in the other two methods display two features: a higher level of stability in cooperation rates and less dependence on past experience. Estimates of the strategies used by subjects reveal that across implementations, even when the discount rate is the same, if interactions are expected to be longer defection increases and the use of the Grim strategy decreases.     

The effect of investment and withdrawal horizons on myopic loss aversion

Using unique survey data, we find that a longer investment horizon (6–10 years and 11+ years) reduces the likelihood of exhibiting myopic loss aversion (MLA) compared to an investment horizon of less than 2 years. In addition, we find that investors with higher levels of assets under management (AUM) are less likely to exhibit MLA compared to the lowest AUM quartile.     

External and internal consistency of choices made in convex time budgets

We evaluate data on choices made from convex time budgets (CTB) in Andreoni and Sprenger (Am Econ Rev 102(7):3333–3356, 2012a) and Augenblick et al. (Q J Econ 130(3):1067–1115, 2015), two influential studies that proposed and applied this experimental technique. We use the weak axiom of revealed preference (WARP) to test for external consistency relative to pairwise choice, and demand, wealth and impatience monotonicity to test for internal consistency. We find that choices made by subjects in the original Andreoni and Sprenger (Am Econ Rev 102(7):3333–3356, 2012a) paper violate WARP frequently; violations of all three internal measures of monotonicity are concentrated in subjects who take advantage of the novel feature of CTB by making interior choices. Wealth monotonicity violations are more prevalent and pronounced than either demand or impatience monotonicity violations. We substantiate the importance of our desiderata of choice consistency in examining effort allocation choices made in Augenblick et al. (Q J Econ 130(3):1067–1115, 2015), where we find considerably more demand monotonicity violations, as well as many classical monotonicity violations which are associated with time inconsistent behavior. We believe that the frequency and magnitude of WARP and monotonicity violations found in the two studies pose important confounds for interpreting and structurally estimating choice patterns elicited through CTB. We encourage researchers employing CTB in present and future experiments to include consistency tests in their design and pre-estimation analysis.     

Patience among children

Recent policy initiatives offer cash payments to children (and often their families) to induce better health and educational choices. These policies implicitly assume that children are especially impatient (i.e., have high discount rates); however, little is known about the nature of children's patience, how it varies across children, and whether children can even make rational inter-temporal choices. This paper examines the inter-temporal choices of 5- to 16-year-old children in an artefactual field experiment. We examine their choices between varying levels of compensation received in 2 or 4 months in the future and in 0 or 2 months in the future. We find that children's choices are consistent with hyperbolic discounting, boys are less patient than girls, older children are more patient and that mathematical achievement test scores, private schooling and parent's patience are not correlated with children's patience. We also find that although more than 25% of children do not make rational inter-temporal choices within a single two-period time frame, we cannot find variables that explain this behavior other than age and standardized mathematical achievement test scores.     

Unemployment and Welfare Participation in a Structural VAR: Rethinking the 1990s in the United States

A report by the Council of Economic Advisers (1997 Council of Economic Advisers. May 1997. “Explaining the decline in welfare receipt, 1993–1996”. May, Washington, DC Executive Office of the President [Google Scholar]) is the first of a group of studies, known as caseload studies, analysing the relationship between the US unemployment rate and the welfare participation rate, with special regard to the 1990s. We examine this relationship in a structural VAR model over the period of 1960–2000 and find that the unemployment rate does not help to predict the welfare participation rate while the converse is more likely to hold. These results are robust to state and year heterogeneity over a period of unprecedented positive correlation between unemployment and welfare participation, i.e. 1990–1998. Further, we find that a shock to the welfare participation rate has a contemporaneous impact on the unemployment rate while the converse is less likely to hold. The main conclusion is that several caseload studies may be based on the wrong assumption that the unemployment rate is an exogenous explanatory variable of the welfare participation rate.     

Empirical and public choice evidence for hyperbolic social discount rates and the implications for intergenerational discounting

The derivation of the correct discount rate for intergenerational projects in Cost Benefit Analysis is particularly contentious. Public choice has resulted in lower discretionary exponential discount rates for many intergenerational projects in Britain and the USA. This is shown to be strong indirect evidence that the true social discount rate may be a hyperbolic (rather than an exponential) function. There is also empirical evidence for this hypothesis. The hyperbolic nature of discounting is also a standard finding in the behavioural sciences. For intergenerational time frames hyperbolic discount rates should be employed together with exponential discount rates in cost-benefit sensitivity analyses.Sincere thanks to Maureen Cropper and Paul Portney for supplying their survey results and to Elaine Barrow and Phillip Judge for graphics assistance. Two anonymous referees also provided valuable comments.     

Patience auctions: the impact of time vs. money bidding on elicited discount rates

We introduce, test, and compare two auction-based methods for eliciting discount rates. In these “patience auctions”, participants bid the smallest future sum they would prefer -or- the longest time they would wait for a reward, rather than receive a smaller, immediate payoff. The most patient bidder receives the delayed reward; all others receive the immediate payoff. These auctions allow us to compare discounting when participants’ attention is focused on the temporal versus monetary dimension of delayed rewards. We find that the estimated parameters in the three most commonly used discount functions (exponential, hyperbolic, and quasi-hyperbolic) differ across these two bidding methods (time-bids vs. money-bids). Specifically, our participants tend to show more impatience under time-bids. Furthermore, we find that people are more likely to exhibit exponential (as opposed to hyperbolic) discounting and exhibit less present bias under time-bids, compared to money-bids. To our knowledge, this paper is the first to directly compare time versus money preference elicitations, within the same subjects, using an incentive-compatible mechanism.     

Interest rate gaps and monetary policy in the work of Henry Thornton: Beyond a retrospective Wicksellian reading *

Abstract

This paper revisits the theory of interest rates propounded by Henry Thornton (1760 – 1815). Particular attention is paid to Thornton's examination of the inflationary effects of the gap between the Bank of England's discount rate and the current rate of profit. The paper shows that Thornton is also concerned, unlike Wicksell, about the consequences of a gap between the Bank of England's discount rate and the effective bank lending rate on the market for loanable funds, which results mainly from the usury laws. Thornton's analyses offer then a framework for regulating the value of money through adjustments to the bank rate.     

Eliciting Individual Discount Rates

Controlled laboratory conditions using monetary incentives have been utilized in previous studies that examine individual discount rates, and researchers have found several apparently robust anomalies. We conjecture that subject behavior in these experiments may be affected by (uncontrolled) factors other than discount rates. We address some experimental design issues and report a new series of experiments designed to elicit individual discount rates. Our primary treatments include: (i) informing subjects of the annual and effective interest rates associated with alternative payment streams, and (ii) informing subjects of current market interest rates. We also test for the effect of real (vs. hypothetical) payments and for the effect of delaying both payment options (vs. offering an immediate payment option). The statistical analysis uses censored data techniques to account for the interactions between field and lab incentives. Each of the information treatments appears to reduce revealed discount rates. When both types of information are provided, annual rates in the interval of 15%–17.5% are revealed, whereas rates of 20%–25% are revealed in the control session. Each of the treatments also lowers the residual variance of subject responses.     

A discrete event simulation to model the cost-utility of fingolimod and natalizumab in rapidly evolving severe relapsing-remitting multiple sclerosis in the UK

Objective: Two disease-modifying therapies are licensed in the EU for use in rapidly-evolving severe (RES) relapsing-remitting multiple sclerosis (RRMS), fingolimod and natalizumab. Here a discrete event simulation (DES) model to analyze the cost-effectiveness of natalizumab and fingolimod in the RES population, from the perspective of the National Health Service (NHS) in the UK, is reported.

Methods: A DES model was developed to track individual RES patients, based on Expanded Disability Status Scale scores. Individual patient characteristics were taken from the RES sub-groups of the pivotal trials for fingolimod. Utility data were in line with previous models. Published costs were inflated to NHS cost year 2015. Owing to the confidential patient access scheme (PAS) discount applied to fingolimod in the UK, a range of discount levels were applied to the fingolimod list price, to capture the likelihood of natalizumab being cost-effective in a real-world setting.

Results: At the lower National Institute of Health and Care Excellence (NICE) threshold of £20,000/quality-adjusted life year (QALY), fingolimod only required a discount greater than 0.8% of list price to be cost-effective. At the upper threshold of £30,000/QALY employed by the NICE, fingolimod was cost-effective if the confidential discount is greater than 2.5%. Sensitivity analyses conducted using fingolimod list-price showed the model to be most sensitive to changes in the cost of each drug, particularly fingolimod.

Conclusions: The DES model shows that only a modest discount to the UK fingolimod list-price is required to make fingolimod a more cost-effective option than natalizumab in RES RRMS.     

Determinants of firm survival: a duration analysis using the generalized gamma distribution

We use parametric duration analysis to study the survival of Austrian firms. We find that hazard rates in both manufacturing and services initially increase, reach a peak after the first year of operation and then decrease with age. The maximum hazard rate is higher in services. We also find differences in hazard rates among different types of manufacturing industries distinguished by the nature of their sunk costs, their reliance on human resources and inputs from external services. Finally, we find that larger initial size and higher market growth, and at the same time lower net entry and declining market concentration prolong the life of an entrant.

What (if any) are the returns to computer use?

Using North American data, we revisit the question first broached by Krueger (1993 Krueger, AB. 1993. How computers have changed the wage structure: evidence from microdata. Quarterly Journal of Economics, 108: 33–60. [Crossref], [Web of Science ®] , [Google Scholar]) and re-examined by DiNardo and Pischke (1997 DiNardo, JE and Pischke, J-S. 1997. The returns to computer use revisited: have pencils changed the wage structure too?. Quarterly Journal of Economics, 112: 291–303. [Crossref], [Web of Science ®] , [Google Scholar]) of whether there exists a real wage differential associated with computer use. Employing a mixed effects model with matched employer–employee data to correct for the fact that workers and workplaces that use computers are self-selected, we find that computer users enjoy an almost 4% wage premium over nonusers. Failure to correct for worker and workplace selection effect leads to a more than twofold overestimate of this premium.     

International Transport of Captured \hbox {CO}_2: Who Can Gain and How Much?

If carbon capture and storage (CCS) is to become a viable option for low-carbon power generation, its deployment will require the construction of dedicated CO₂ transport infrastructure. In a scenario of large-scale deployment of CCS in Europe by 2050, the optimal (cost-minimising) CO₂ transport network would consist of large international bulk pipelines from the main CO₂ source regions to the CO₂ sinks in hydrocarbon fields and saline aquifers, which are mostly located in the North Sea. In this paper, we use a Shapley value approach to analyse the multilateral negotiation process that would be required to develop such jointly optimised CO₂ infrastructure. First, we find that countries with excess storage capacity capture 38–45 % of the benefits of multilateral coordination, implying that the resource rent of a depleted hydrocarbon field (when used for CO₂ storage) is roughly $${\$}1$$ per barrel of original recoverable oil reserves, or $${\$}2$$ per boe (barrel of oil equivalent) of original recoverable gas reserves. This adds 25–600 % to current estimates of CO₂ storage cost. Second, countries with a strategic transit location capture 19 % of the rent in the case of national pipeline monopolies. Liberalisation of CO₂ pipeline construction at EU level could eliminate the transit rent and is shown to reduce by two-thirds the differences between countries in terms of cost per tonne of CO₂ exported. Reaching agreement on such liberalisation may be politically challenging, since the payoffs are shown to be strongly divergent across countries.     

What Explains Herd Behavior in the Chinese Stock Market?

This article examines the causes of herd behavior in the Chinese stock market. Using the nonlinear model of Chang, Cheng, and Khorana [2000 Chang, E. C., J. W. Cheng, and A. Khorana. “An Examination of Herd Behavior in Equity Markets: An International Perspective.” Journal of Banking and Finance, 24, (2000), pp. 1651–1679.[Crossref], [Web of Science ®] , [Google Scholar]], the authors of this article find robust evidence of herding in both the up and down markets. They contribute to the existing literature by exploring the underlying reasons for herding in China. It is shown that analyst recommendation, short-term investor horizon, and risk are the principal causes of herding. However, the authors cannot find evidence that relates herding to firm size, nor can they detect significant differences in herding between state-owned enterprises and non–state-owned enterprises.