Plausible Set Research Articles

Should Alberta upgrade oil sands bitumen? An integrated life cycle framework to evaluate energy systems investment tradeoffs

The inclusion of greenhouse gas (GHG) emissions costs in energy systems investment decision-making requires the development of a framework that accounts for GHG and economic tradeoffs. This paper develops such a framework by integrating partial cost–benefit analysis with life cycle assessment to explore the question of whether bitumen should be upgraded in the Canadian province of Alberta to produce synthetic crude oil (SCO), or blended with light hydrocarbons to produce lower-quality diluted bitumen (dilbit). The net present value (NPV) of these options is calculated from the stakeholder perspectives of the oil sands industry, the Alberta public, and a climate-concerned Alberta resident. This calculation includes monetized GHG emissions costs stemming from a hypothetical economy-wide GHG price, and a sensitivity analysis explores the effects of variations in technical and economic conditions on stakeholders’ preferences. We find that under most plausible sets of conditions, industry would prefer the dilution option, while the climate-concerned Alberta resident would prefer the upgrading option. In contrast, the preferences of the general Alberta public depend on the values of key variables (e.g., the SCO-dilbit price differential). Key drivers of differences among stakeholders’ preferences include different perceptions of risks and responsibilities for life cycle GHG emissions.

Concentrated Equilibrium and Intraday Patterns in Financial Markets

We introduce endogenous participation of market makers into a Kyle-type model with long-lived asymmetric information. The main result is that under a plausible parameter setting, the trading volume and price volatility show a U-shape with respect to time, meaning that the market trading concentrates at opening and closing sessions. Our model effectively provides a theoretical explanation on the stylized fact that trading concentration occurs at the opening and closing periods in financial markets.

BOOK REVIEWS

BOOK REVIEWS

The U/Pb ratio of the Earth's mantle—A signature of late volatile addition

The 238U/204Pb ratio of the Earth's mantle is conventionally seen as reflecting the loss of lead to the Earth's core, implying that this element is siderophile. A contrasting view holds that lead may be depleted because it did not fully condense at the accretion temperatures of the early Earth. Experiments reported here show that lead is indeed quite siderophile at high temperature. At the same time, it is noted that no plausible set of physical conditions exists where the present-day abundances of all moderately volatile elements of the mantle could have been in chemical equilibrium with a metallic iron melt. It is argued that a large proportion of the moderately volatile elements, including Pb, were added late, during the waning stages of core formation. In consequence, caution is advised in using the 238U/204Pb and the Pb isotope ratios of the mantle to date the differentiation of the Earth in silicate mantle and metallic core (Hofmann, 2001).

A Bayesian multiple imputation method for handling longitudinal pesticide data with values below the limit of detection

Environmental and biomedical research often produces data below the limit of detection (LOD), or left-censored data. Imputing explicit values for values < LOD in a multivariate setting, such as with longitudinal data, is difficult using a likelihood-based approach. A Bayesian multiple imputation (MI) method is introduced to handle left-censored multivariate data. A Gibbs sampler, which uses an iterative process, is employed to simulate the target multivariate distribution within a Bayesian framework. Following convergence, multiple plausible data sets are generated for analysis by standard statistical methods outside of a Bayesian framework. With explicit imputed values available variables can be analyzed as outcomes or predictors. We illustrate a practical application using longitudinal data from the Community Participatory Approach to Measuring Farmworker Pesticide Exposure (PACE3) study to evaluate the association between urinary acephate concentrations (indicating pesticide exposure) and self-reported potential pesticide poisoning symptoms. Additionally, a simulation study is used to evaluate the sampling property of the estimators for distributional parameters as well as regression coefficients estimated with the generalized estimating equation (GEE) approach. Results demonstrated that the Bayesian MI estimates performed well in most settings, and we recommend the use of this valid and feasible approach to analyze multivariate data with values < LOD.

Detecting natural occlusion boundaries using local cues

Occlusion boundaries and junctions provide important cues for inferring three-dimensional scene organization from two-dimensional images. Although several investigators in machine vision have developed algorithms for detecting occlusions and other edges in natural images, relatively few psychophysics or neurophysiology studies have investigated what features are used by the visual system to detect natural occlusions. In this study, we addressed this question using a psychophysical experiment where subjects discriminated image patches containing occlusions from patches containing surfaces. Image patches were drawn from a novel occlusion database containing labeled occlusion boundaries and textured surfaces in a variety of natural scenes. Consistent with related previous work, we found that relatively large image patches were needed to attain reliable performance, suggesting that human subjects integrate complex information over a large spatial region to detect natural occlusions. By defining machine observers using a set of previously studied features measured from natural occlusions and surfaces, we demonstrate that simple features defined at the spatial scale of the image patch are insufficient to account for human performance in the task. To define machine observers using a more biologically plausible multiscale feature set, we trained standard linear and neural network classifiers on the rectified outputs of a Gabor filter bank applied to the image patches. We found that simple linear classifiers could not match human performance, while a neural network classifier combining filter information across location and spatial scale compared well. These results demonstrate the importance of combining a variety of cues defined at multiple spatial scales for detecting natural occlusions.

PRM45 Utility Estimation for Visual Acuity Health States: An Original and Pragmatic Approach to Transpose Published Evidence Into a More Flexible Estimation

The NICE reference case stipulates cost-utility analysis as the preferred form of economic evaluation, with health effects expressed in QALYs and health states valued using a validated choice-based method such as the time-trade-off (TTO). The evidence-base describing the impact of visual impairment (VI) on quality-of-life is very limited. To date, the Czoski-Murray et al. (2009) utility values for 4 visual health severity groups are considered the most plausible set of utility values for use in eye-disorder economic models. These utility values, originally elicited through simulating VI similar to that associated with wet age-related macular degeneration, were recently applied in other retinal disorders such as diabetic macular edema. The objective of our analysis was to refine the mapping of utilities onto visual acuity (VA). OLS regression models were built to estimate the relationship between mid-point VA of 4 visual health severity groups and mean TTO scores as described in the literature. Linear and non-linear approaches for utility estimation as a function of the number of VA letters were explored. The linear regression for utility estimation was found to be statistically significant. The beta-coefficient for mid-point VA was 0.0054 (p=0.030) and 0.2864 for the constant term (p=0.034). Linear regression estimates were used to predict the utility value for 6 pre-specified VA health states: VA1 (0.766); VA2 (0.671); VA3 (0.616); VA4 (0.562); VA5 (0.507); VA6 (0.382). Published evidence on utility values for deterministic visual health severity groups may not easily transpose to alternative vision health-states. Our analysis demonstrated an original approach for utility estimation allowing a more flexible and robust method to map previously elicited VA-associated utilities onto alternate VA health-states. This method allows wider applicability of VA-associated utility estimation in other eye disorders characterized by VA impairment such as vitreomacular traction and macular hole.

Late Proterozoic juvenile arc metatonalite and adakitic intrusions in the Sør Rondane Mountains, eastern Dronning Maud Land, Antarctica

This study is a detailed investigation of the petrology and geochronology of the Late Proterozoic metatonalite in the Sør Rondane Mountains, eastern Dronning Maud Land, Antarctica. Metatonalite is dominant over roughly 100×20km2 area in the southwestern end of the mountain range and is classified into five lithologies: gneissose Bt–Hbl metatonalite, weak gneissose Hbl–Bt metatonalite, Hbl metagabbro, Hbl–Bt tonalitic gneiss, and Bt metatonalite. The gneissose Bt–Hbl metatonalite is the main lithotype widely distributed over this area, which is geochemically categorized as low-K tholeiitic granitoid. Petrological studies suggest that the tholeiitic magma was derived from low-K basalt melting at the crustal depth, and the most plausible tectonic setting is a juvenile oceanic arc. The other four metaplutonic rocks are scattered as stocks or small intrusions in this area. They are geochemically regarded as calc-alkaline adakites related to oceanic slab melting. U–Pb SHRIMP zircon ages of the tholeiitic metatonalite are concentrated at 998–995Ma, whereas the calc-alkaline adakitic rocks are younger and divided between ages 945–920Ma and 772Ma. We believe that the tholeiitic metatonalite was formed first as a juvenile arc component between 998 and 995Ma, followed by adakitic magmatism and oceanic slab melting at 945–920Ma and 772Ma. Magmatism during this stage is not recorded in the western to central Dronning Maud Land. Moreover, the exposure of an adakitic equivalent continues at the farther eastern side of the Sør Rondane Mountains. This suggests that the tectonic framework of the Sør Rondane Mountains, eastern Dronning Maud Land, is different from the western to central Dronning Maud Land.

On the need for automated multiobjective optimization and uncertainty estimation of glacier mass balance models

Physically based models are valuable tools for exploring the detailed spatial and temporal responses of glaciers and ice sheets to climate forcing. However, while the last two decades have seen considerable progress in the development of increasingly sophisticated numerical descriptions, very little attention has been given to simulation uncertainty. In particular, glaciological models have traditionally been calibrated (or “tuned”) in order to identify a single set of parameters (e.g., snow density, surface albedo, temperature lapse rate) such that the model's behavior closely matches real‐world observations. The present study disputes this classical approach by demonstrating that it is often difficult (if not impossible) to find a single “best” solution. Instead, multiple equally plausible parameter sets will usually exist. To address this limitation, we present a novel application of a calibration technique previously not used in glacial modeling – multiobjective optimization – designed to identify multiple optimal parameter sets that fit different characteristics of available observations, thereby enabling an assessment of the uncertainty associated with predictions. The strength and applicability of our approach is illustrated through the implementation of a surface mass balance model for two glaciers in Svalbard: Midre Lovénbreen and Kongsvegen. The model is forced using the ERA‐40 reanalysis and calibrated against available mass balance measurements. The overall uncertainty range in modeled cumulative annual surface mass balance is −7.84 to −14.02 m w.e. for Midre Lovénbreen (over the period 1968–2001) and −0.91 to +9.80 m w.e. for Kongsvegen (over the period 1987–2001). The calibrated model is used to extend the mass balance records of the two glaciers back to the beginning of the ERA‐40 reanalysis, giving a cumulative loss of loss of 13.2 ± 3.3 m w.e. for Midre Lovénbreen and a cumulative gain of 5.3 ± 3.4 m w.e. for Kongsvegen over the period 1958–2001. The multiobjective optimization results also indicate that current mass balance models may contain structural inadequacies relating to how the mass balance gradient is simulated.

Interactions between the spatial and temporal stimulus factors that influence multisensory integration in human performance

In natural environments, human sensory systems work in a coordinated and integrated manner to perceive and respond to external events. Previous research has shown that the spatial and temporal relationships of sensory signals are paramount in determining how information is integrated across sensory modalities, but in ecologically plausible settings, these factors are not independent. In the current study, we provide a novel exploration of the impact on behavioral performance for systematic manipulations of the spatial location and temporal synchrony of a visual-auditory stimulus pair. Simple auditory and visual stimuli were presented across a range of spatial locations and stimulus onset asynchronies (SOAs), and participants performed both a spatial localization and simultaneity judgment task. Response times in localizing paired visual-auditory stimuli were slower in the periphery and at larger SOAs, but most importantly, an interaction was found between the two factors, in which the effect of SOA was greater in peripheral as opposed to central locations. Simultaneity judgments also revealed a novel interaction between space and time: individuals were more likely to judge stimuli as synchronous when occurring in the periphery at large SOAs. The results of this study provide novel insights into (a) how the speed of spatial localization of an audiovisual stimulus is affected by location and temporal coincidence and the interaction between these two factors and (b) how the location of a multisensory stimulus impacts judgments concerning the temporal relationship of the paired stimuli. These findings provide strong evidence for a complex interdependency between spatial location and temporal structure in determining the ultimate behavioral and perceptual outcome associated with a paired multisensory (i.e., visual-auditory) stimulus.

A Symmetric Dual Feedback System Provides a Robust and Entrainable Oscillator

Many organisms have evolved molecular clocks to anticipate daily changes in their environment. The molecular mechanisms by which the circadian clock network produces sustained cycles have extensively been studied and transcriptional-translational feedback loops are common structures to many organisms. Although a simple or single feedback loop is sufficient for sustained oscillations, circadian clocks implement multiple, complicated feedback loops. In general, different types of feedback loops are suggested to affect the robustness and entrainment of circadian rhythms.To reveal the mechanism by which such a complex feedback system evolves, we quantify the robustness and light entrainment of four competing models: the single, semi-dual, dual, and redundant feedback models. To extract the global properties of those models, all plausible kinetic parameter sets that generate circadian oscillations are searched to characterize their oscillatory features. To efficiently perform such analyses, we used the two-phase search (TPS) method as a fast and non-biased search method and quasi-multiparameter sensitivity (QMPS) as a fast and exact measure of robustness to uncertainty of all kinetic parameters.So far the redundant feedback model has been regarded as the most robust oscillator, but our extensive analysis corrects or overcomes this hypothesis. The dual feedback model, which is employed in biology, provides the most robust oscillator to multiple parameter perturbations within a cell and most readily entrains to a wide range of light-dark cycles. The kinetic symmetry between the dual loops and their coupling via a protein complex are found critically responsible for robust and entrainable oscillations. We first demonstrate how the dual feedback architecture with kinetic symmetry evolves out of many competing feedback systems.

North American CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; exchange: inter-comparison of modeled estimates with results from a fine-scale atmospheric inversion

Abstract. Atmospheric inversion models have the potential to quantify CO2 fluxes at regional, sub-continental scales by taking advantage of near-surface CO2 mixing ratio observations collected in areas with high flux variability. This study presents results from a series of regional geostatistical inverse models (GIM) over North America for 2004, and uses them as the basis for an inter-comparison to other inversion studies and estimates from biospheric models collected through the North American Carbon Program Regional and Continental Interim Synthesis. Because the GIM approach does not require explicit prior flux estimates and resolves fluxes at fine spatiotemporal scales (i.e. 1° × 1°, 3-hourly in this study), it avoids temporal and spatial aggregation errors and allows for the recovery of realistic spatial patterns from the atmospheric data relative to previous inversion studies. Results from a GIM inversion using only available atmospheric observations and a fine-scale fossil fuel inventory were used to confirm the quality of the inventory and inversion setup. An inversion additionally including auxiliary variables from the North American Regional Reanalysis found inferred relationships with flux consistent with physiological understanding of the biospheric carbon cycle. Comparison of GIM results with bottom-up biospheric models showed stronger agreement during the growing relative to the dormant season, in part because most of the biospheric models do not fully represent agricultural land-management practices and the fate of both residual biomass and harvested products. Comparison to earlier inversion studies pointed to aggregation errors as a likely source of bias in previous sub-continental scale flux estimates, particularly for inversions that adjust fluxes at the coarsest scales and use atmospheric observations averaged over long periods. Finally, whereas the continental CO2 boundary conditions used in the GIM inversions have a minor impact on spatial patterns, they have a substantial impact on the continental carbon budget, with a difference of 0.8 PgC yr−1 in the total continental flux resulting from the use of two plausible sets of boundary CO2 mixing ratios. Overall, this inter-comparison study helps to assess the state of the science in estimating regional-scale CO2 fluxes, while pointing towards the path forward for improvements in future top-down and bottom-up modeling efforts.

Application of a random forests (RF) method as a new approach for variable selection and modelling in a QSRR study to predict the relative retention time of some polybrominated diphenylethers (PBDEs)

In this work, the method of random forests (RF) was applied for modeling and prediction of the relative retention time of some polybrominated diphenylethers (PBDEs) with descriptors calculated from the molecular structure alone. The effects of tuning parameters such as the number of trees (nt) and the number of randomly selected variables to split each node (m) were investigated. The obtained results showed that the pair (m = 38, nt = 500) can be considered as a plausible setting so that the generalization error was minimal. Also, the importance level of different descriptors was evaluated using RF to simplify the model. The performance of the RF model was compared with the artificial neural network (ANN). Both ANN and RF methods provided accurate predictions, although more accurate results were obtained by the RF model. The determination coefficients of the test set, obtained by the ANN and RF methods, are 0.9619 and 0.9707 respectively.

Fuel production from CO2 using solar-thermal energy: system level analysis

Sunshine to Petrol (S2P) is a technology framework using a concentrated solar energy source and energy depleted CO2 and water feedstocks for producing liquid hydrocarbon fuels as sustainable alternatives to vulnerable and limited supplies of conventional petroleum. S2P encompasses numerous design configurations that integrate several unit operations to thermochemically convert CO2 and water to a final energized marketable product. In an earlier paper, hereafter referred to as Paper I, we established both a baseline system design and a methodology for evaluating system efficiencies, economics, and lifecycle impacts. Therein we demonstrated that design details of the balance of system following the initial solar to chemical conversion could have significant impact on full system efficiencies, which largely determine both economics and the lifecycle. Here we assess and compare results from three types of choices in the system configuration: the initial solar to chemical conversion, separations, and the final product. Each design option begins with CO2 capture. Options A–C differ in the initial solar splitting: (A) splitting CO2, (B) splitting H2O and (C) splitting both CO2 and H2O. Significantly, we find that splitting both has notable advantages over splitting just one, in efficiency and consequently in derived minimum selling price (MSP) of a methanol product. Option D splits both but replaces the methanol end-product with likely higher value Fischer Tropsch (FT) liquids. The production of the FT end product comes with a small decrease in solar to fuel energy efficiency (∼3.5% relative decrease from option C) and a small relative increase in the energy equivalent MSP (∼5%). Importantly, we find that in all options, the primary contributor to MSP is the cost of capital for the solar thermochemical sub-system (including the solar collectors) and not in the balance of system components or operating costs. The advantages of options C and D, over the baseline A, stem primarily from the decrease in CO2 to recover and recycle, motivating changing the separation component and replacing conventional and mature MEA-based CO2 separations with a technology to recover the minor component, CO. Of significance, we find that the choice of separations can yield considerable system benefits; for example in option F, splitting both CO2 and H2O, and separating CO from the produced CO2/CO mix, the system efficiency increases by 10% relative to option C for a resource-efficient full system solar to liquid fuel energy efficiency of 12.9%, and the MSP decreased by 18%. Motivated to determine if attractive economics are plausible and to identify the largest opportunities to reduce cost, we show results of a sensitivity analysis for key system and economic parameters. Finally, we construct alternate scenarios that consist of reductions in the most sensitive parameters, which include: solar utility prices, the solar dish–CR5 price, and the interest rate. The most optimistic but plausible parameter set yields an encouraging MSP for methanol of USD 4.24 per GGE (gallon of gasoline energy equivalent). The promising configuration splits both CO2 and H2O, separates the minority component CO, reduces solar derived utility costs an anticipated 60%, achieves 20% reductions in estimated manufacturing cost of the dish/CR5 component, and obtains a favorable 6.4% interest rate.

Catchment responses to plausible parameters and input data under equifinality in distributed rainfall‐runoff modeling

AbstractIn a hydrological simulation using a complex model, equifinality is likely to occur in many different ways, due to various sources associated with the model structure, parameter as well as data uncertainties involved in modeling process. This study aims to demonstrate the equifinality problem in streamflow prediction with a distributed rainfall‐runoff model and also investigate the effect of parameter and input uncertainties on an internal catchment response in time and space under the equifinality condition. For this objective, several experiments were carried out step by step as follows. First, we estimated plausible parameter sets, which lead to similarly good objective function values, using the shuffled complex evolution metropolis (SCEM‐UA) algorithm and also generated plausible input scenarios with different spatial patterns from radar rainfall field, which showed minimum runoff errors. Then, we adopted a computational tracer method based on a time‐space accounting scheme, combined with a distributed model for analyzing how a catchment behaves under a given equifinality condition by parameter and input uncertainties. It was found that the global responses of a catchment to the predefined equifinality factors were very similar; all simulated hydrographs were almost identical in spite of the different model parameter values and different spatial patterns of rainfall data. On the other hand, the internal catchment responses, tracked by the computational tracer method, were sensitive to plausible scenarios. The results of the internal catchment behavior show that the distributed rainfall‐runoff model has multiple alternative flow pathways, providing identical hydrographs in time and space when the rainfall over the catchment transforms into runoff. Our approach can be used to understand catchment responses to various uncertainty sources by visualizing the spatiotemporal runoff generation process at the watershed scale. Copyright © 2011 John Wiley &amp; Sons, Ltd.

Thermochemical convection in Earth’s inner core

SUMMARY The dynamics of Earth’s inner core depends critically on whether it is stably stratified or unstably stratified. We propose here a general analysis of the thermal evolution of the inner core. Whether the geotherm in the inner core is superadiabatic or not depends on the inner core solidification rate, on the thermal diffusivity of iron at inner core conditions, and on the ratio of the Clapeyron slope to the adiabatic gradient in the inner core. The temperature field within the inner core can be destabilizing—and could drive convection—if the growth of the inner core is fast enough. The effect of radiogenic heating is probably small, and, perhaps surprisingly, can even stabilize the inner core against convection. The uncertainties are such that it is not possible at present to conclude about the likelihood of thermal convection in the inner core, but recent estimates of the Core–Mantle Boundary (CMB) heat flux and inner core conductivity favour convection. Thermal convection is more likely early in the inner core history, a consequence of the secular decrease in cooling rate of the core. In addition, solidification-induced partitioning of the light elements may induce a stable density stratification within the inner core. We develop a numerical model of thermochemical convection in a growing inner core, which couples the evolution and dynamics of the inner core with the thermal and compositional evolution of the outer core. Melting and crystallization associated with deformation of the Inner Core Boundary (ICB) would be of importance for the style of convection if the viscosity is large, but we focus here on the case of low viscosity for which phase change associated with dynamic topography at the ICB is expected to play a secondary role. In this regime, convection is typical of high Rayleigh number internally heated convection, with cold plumes falling from the ICB. Several possible scenarios can lead to a layered inner core, either because of cessation of thermal convection due to the decrease in cooling rate of the core, or because of a compositional stratification which can confine convection in the deep inner core, or stabilize the whole inner core. For each of these scenarios, it is possible to find plausible sets of parameters (inner core age, viscosity, magnitude of the compositional stratification) for which the radius at which convection stops corresponds to the radius of the seismically inferred innermost inner core.

Characterizing the efficient points without closedness or free-disposability

Many multicriteria problems in economics and finance require that efficient solutions be found. A recent contribution to production theory estab- lished a characterization of efficient points under closedness and free-disposability (Bonnisseau and Crettez in Econ Theory 31(2):213-223, 2007, Theorem 1). However, as will be shown using a number of examples, these results cannot be applied to simple and plausible production sets, nor can they be extended to other classic multicriteria problems such as those arising in optimal portfolio theory and bargaining theory. To address these limitations, a reformulation of the above theorem without closedness or free-disposability is proposed. This enables efficient solutions for a wider range of multicriteria problems to be identified.

V = Land Intuitive Plausibility in set Theory. A Case Study

AbstractWhat counts as an intuitively plausible set theoretic content (notion, axiom or theorem) has been a matter of much debate in contemporary philosophy of mathematics. In this paper I develop a critical appraisal of the issue. I analyze first R. B. Jensen's positions on the epistemic status of theaxiom of constructibility. I then formulate and discuss a view of intuitiveness in set theory that assumes it to hinge basically on mathematicalsuccess. At the same time, I present accounts of set theoretic axioms and theorems formulated in non-strictly mathematical terms, e.g., by appealing to theiterative conceptof set and/or to overall methodological principles, likeunifyandmaximize, and investigate the relation of the latter to success in mathematics.

DICER: A tool for analyzing climate policies

Modeling the economy and the planet's climate involves a great number of variables and parameters, some of them very uncertain given the current stage of knowledge regarding technology and the science of climate. The DICER model (or DICE-Regional) is a recently constructed Integrated Assessment Model (IAM), based on the structure of the DICE family of models, which was developed as an instrument for the analysis of uncertainties in climate policy. This paper aims to describe the basic version of DICER on which future developments addressing uncertainty in climate policy analysis will be based. Our results suggest a few interesting conclusions when compared to other IAMs: (i) under a plausible set of assumptions and parameters DICER indicates that an optimal global climate policy would imply higher costs of climate change in the short run but a faster (and more expensive) decarbonization process in all regions, resulting in a faster stabilization of the climate; (ii) lower peak temperatures that occur earlier in time; (iii) considerable sensitivity of results to key parameters such as climate sensitivity, but lower than expected sensitivity to the social discount rate.

MONEY, SOCIAL STATUS AND ENDOGENOUS GROWTH IN A GENERALIZED CASH‐IN‐ADVANCE MODEL

AbstractThis paper analytically examines the equilibrium growth effect of money/inflation in a standard one‐sector AK model of endogenous growth with the most generalized cash‐in‐advance constraint and relative wealth‐induced preferences for social status. We show that on the economy's unique balanced growth equilibrium path, the sign of the correlation between money and output growth depends crucially on: (i) the intertemporal elasticity of substitution in consumption; and (ii) the liquidity‐constrained ratio of consumption to investment expenditure. Moreover, our model economy always exhibits a positive output–growth effect in response to changes of the strength for social status. We also undertake numerical experiments to assess the quantitative importance of our theoretical results under an empirically plausible set of parameters.