Future Cost (future + cost)

Distribution by Scientific Domains


Selected Abstracts


Autotomy-induced life history plasticity in band-legged ground cricket Dianemobius nigrofasciatus

ENTOMOLOGICAL SCIENCE, Issue 1 2010
Nobuhiro MATSUOKA
Abstract Crickets can autotomize their limbs when attacked by predators. This enables them to escape death, but imposes a short-term cost on their escape speed and a long-term cost on their future mating ability. Therefore, adaptive response compensated for the cost of autotomy might be advantageous for autotomized individuals. In the present study, we examined whether autotomy induced life history plasticities compensating for the future cost in the band-legged ground cricket Dianemobius nigrofasciatus. Life history traits of D. nigrofasciatus were compared between autotomized and intact individuals. The developmental time and head width of the individuals that were autotomized as fourth instar nymphs were significantly shorter and smaller, respectively, than those of intact individuals. However, the adult longevity, number of eggs laid and oviposition schedule did not vary between autotomized and intact individuals. In addition, there was no difference between individuals autotomized at the fourth instar and adult stages in these three traits. Early maturation in the autotomized individuals might be advantageous through reducing the risk of predation owing to the shorter period in nymphal stages. The cost of small body size in the autotomized females might not be so great because of no significant difference in fecundity between autotomized and intact individuals. However, the cost of small body size was unclear in the autotomized males because in general larger males were preferred by females. These results indicated autotomy-induced life history that might reduce the cost of autotomy. [source]


Is it possible to identify early predictors of the future cost of chronic arthritis?

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2009
The VErA project
Abstract This study was conducted to identify early predictors of the total cost of inflammatory arthritis (IA). One hundred and eighty patients affected by undifferentiated arthritis (UA) or rheumatoid arthritis (RA) were included in the French Very Early rheumatoid Arthritis (VErA) cohort between 1998 and 2001. Health economic data for 2003 were collected using a patient self-questionnaire. Results were analysed in terms of direct, indirect and total costs in 2003 euros (2003,) for the population as a whole and in diagnostic subgroups. A payor perspective (the French National Health Insurance, in this case) was adopted. Multiple linear regression models were used to identify predictors of total cost from among the criteria assessed on recruitment. Results of the study showed that for the study population as a whole, the mean total cost was ,4700 per patient. The costs attributable to the RA and UA sub-groups were ,5928 and ,2424 per patient, respectively. In a univariate analysis, certain parameters were significantly correlated with a higher cost of illness. In the multivariate analysis, some of these parameters were further identified as being predictive of higher cost. Two strong significant, early predictors of total cost were identified: higher pain (P = 0.002) and the presence of rheumatoid factor (P = 0.004). In the RA sub-group, lower grip strength of the dominant hand (P = 0.039) was another predictor of the illness's subsequent economic impact. In conclusion, our data show that simple clinical and laboratory parameters can be used early in the course of IA to predict the condition's impact on healthcare budgets. [source]


Shortest path stochastic control for hybrid electric vehicles

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 14 2008
Edward Dean Tate Jr
Abstract When a hybrid electric vehicle (HEV) is certified for emissions and fuel economy, its power management system must be charge sustaining over the drive cycle, meaning that the battery state of charge (SOC) must be at least as high at the end of the test as it was at the beginning of the test. During the test cycle, the power management system is free to vary the battery SOC so as to minimize a weighted combination of fuel consumption and exhaust emissions. This paper argues that shortest path stochastic dynamic programming (SP-SDP) offers a more natural formulation of the optimal control problem associated with the design of the power management system because it allows deviations of battery SOC from a desired setpoint to be penalized only at key off. This method is illustrated on a parallel hybrid electric truck model that had previously been analyzed using infinite-horizon stochastic dynamic programming with discounted future cost. Both formulations of the optimization problem yield a time-invariant causal state-feedback controller that can be directly implemented on the vehicle. The advantages of the shortest path formulation include that a single tuning parameter is needed to trade off fuel economy and emissions versus battery SOC deviation, as compared with two parameters in the discounted, infinite-horizon case, and for the same level of complexity as a discounted future-cost controller, the shortest-path controller demonstrates better fuel and emission minimization while also achieving better SOC control when the vehicle is turned off. Linear programming is used to solve both stochastic dynamic programs. Copyright 2007 John Wiley & Sons, Ltd. [source]


Analysing absence behaviour using event history models

MANAGERIAL AND DECISION ECONOMICS, Issue 3 2004
Tim Barmby
This paper analyses the absence behaviour of a group of industrial workers. Part of their remuneration scheme comprises an experience rated sick-pay scheme (linking level of sickpay to past absence) which determines the cost of a day's absence for a worker, both contemporaneously and in terms of expected future cost. This cost is explicitly computed for each worker and we show that this cost is negatively related to absence. Using an event history model with a Markov structure for the absence histories the size of this effect is shown to depend on the state occupied. Copyright 2004 John Wiley & Sons, Ltd. [source]


OBESITY AND NUTRIENT CONSUMPTION: A RATIONAL ADDICTION?

CONTEMPORARY ECONOMIC POLICY, Issue 3 2007
TIMOTHY J. RICHARDS
Recent research shows that the dramatic rise in obesity in the United States is due more to the overconsumption of unhealthy foods than underactivity. This study tests for an addiction to food nutrients as a potential explanation for the apparent excessive consumption. A random coefficients (mixed) logit model is used to test a multivariate rational addiction model. The results reveal a particularly strong addiction to carbohydrates. The implication of this finding is that price-based policies, sin taxes, or produce subsidies that change the expected future costs and benefits of consuming carbohydrate-intensive foods may be effective in controlling excessive nutrient intake. (JEL D120, I120, C230) [source]


LARGE IS BEAUTIFUL: HORIZONTAL MERGERS FOR BETTER EXPLOITATION OF PRODUCTION SHOCKS,

THE JOURNAL OF INDUSTRIAL ECONOMICS, Issue 1 2008
WEN ZHOU
The profitability of horizontal mergers is investigated in a situation in which firms face a production shock and therefore are uncertain about their future costs. I show that, due to production rationalization, small-scale mergers can be profitable if the uncertainty is large. The efficiency gain in production also implies benign welfare consequences. Under cost uncertainty, a profitable merger always improves social welfare if no more than half of the industry's firms are allowed to merge. Finally, I show that the incentives to merge depend on the information structure. Firms are less likely to merge when they possess more information. [source]