When Conscientiousness Isn’t Enough: Emotional Exhaustion and Performance Among Call Center Customer Service Representatives

The authors examined the relationship of the interaction between emotional exhaustion and conscientiousness with objectively-measured call volume performance and subjectively-measured service quality ratings among 92 call center customer service representatives (CSR’s) of a financial services institution. Results supported the interactive effects on call volume but not service quality. Specifically, the relationship between emotional exhaustion and call volume was stronger among high- than low-conscientiousness CSR’s. Among CSR’s reporting low levels of emotional exhaustion, those high in conscientiousness achieved higher call volumes than those low in conscientiousness. In contrast, among CSR’s reporting high levels of emotional exhaustion, those high in conscientiousness achieved lower call volumes than those low in conscientiousness. Implications for both the personality and stress literatures are discussed. Practical implications for human resources managers also are offered.     

A Survey of Approaches for Assessing and Managing the Risk of Extremes

In this paper, we review methods for assessing and managing the risk of extreme events, where extreme events are defined to be rare, severe, and outside the normal range of experience of the system in question. First, we discuss several systematic approaches for identifying possible extreme events. We then discuss some issues related to risk assessment of extreme events, including what type of output is needed (e.g., a single probability vs. a probability distribution), and alternatives to the probabilistic approach. Next, we present a number of probabilistic methods. These include: guidelines for eliciting informative probability distributions from experts; maximum entropy distributions; extreme value theory; other approaches for constructing prior distributions (such as reference or noninformative priors); the use of modeling and decomposition to estimate the probability (or distribution) of interest; and bounding methods. Finally, we briefly discuss several approaches for managing the risk of extreme events, and conclude with recommendations and directions for future research.     

Differences in Pharmacokinetics Between Children and Adults—II. Children''s Variability in Drug Elimination Half-Lives and in Some Parameters Needed for Physiologically-Based Pharmacokinetic Modeling

In earlier work we assembled a database of classical pharmacokinetic parameters (e.g., elimination half-lives; volumes of distribution) in children and adults. These data were then analyzed to define mean differences between adults and children of various age groups. In this article, we first analyze the variability in half-life observations where individual data exist. The major findings are as follows. The age groups defined in the earlier analysis of arithmetic mean data (0-1 week premature; 0-1 week full term; 1 week to 2 months; 2-6 months; 6 months to 2 years; 2-12 years; and 12-18 years) are reasonable for depicting child/adult pharmacokinetic differences, but data for some of the earliest age groups are highly variable. The fraction of individual children's half-lives observed to exceed the adult mean half-life by more than the 3.2-fold uncertainty factor commonly attributed to interindividual pharmacokinetic variability is 27% (16/59) for the 0-1 week age group, and 19% (5/26) in the 1 week to 2 month age group, compared to 0/87 for all the other age groups combined between 2 months and 18 years. Children within specific age groups appear to differ from adults with respect to the amount of variability and the form of the distribution of half-lives across the population. The data indicate departure from simple unimodal distributions, particularly in the 1 week to 2 month age group, suggesting that key developmental steps affecting drug removal tend to occur in that period. Finally, in preparation for age-dependent physiologically-based pharmacokinetic modeling, nationally representative NHANES III data are analyzed for distributions of body size and fat content. The data from about age 3 to age 10 reveal important departures from simple unimodal distributional forms-in the direction suggesting a subpopulation of children that are markedly heavier than those in the major mode. For risk assessment modeling, this means that analysts will need to consider "mixed" distributions (e.g., two or more normal or log-normal modes) in which the proportions of children falling within the major versus highweight/fat modes in the mixture changes as a function of age. Biologically, the most natural interpretation of this is that these subpopulations represent children who have or have not yet received particular signals for change in growth pattern. These apparently distinct subpopulations would be expected to exhibit different disposition of xenobiotics, particularly those that are highly lipophilic and poorly metabolized.     

Combining Probability Distributions From Experts in Risk Analysis

This paper concerns the combination of experts' probability distributions in risk analysis, discussing a variety of combination methods and attempting to highlight the important conceptual and practical issues to be considered in designing a combination process in practice. The role of experts is important because their judgments can provide valuable information, particularly in view of the limited availability of hard data regarding many important uncertainties in risk analysis. Because uncertainties are represented in terms of probability distributions in probabilistic risk analysis (PRA), we consider expert information in terms of probability distributions. The motivation for the use of multiple experts is simply the desire to obtain as much information as possible. Combining experts' probability distributions summarizes the accumulated information for risk analysts and decision-makers. Procedures for combining probability distributions are often compartmentalized as mathematical aggregation methods or behavioral approaches, and we discuss both categories. However, an overall aggregation process could involve both mathematical and behavioral aspects, and no single process is best in all circumstances. An understanding of the pros and cons of different methods and the key issues to consider is valuable in the design of a combination process for a specific PRA. The output, a combined probability distribution, can ideally be viewed as representing a summary of the current state of expert opinion regarding the uncertainty of interest.     

Licensed house manager skills/competences and the management development process in Bass Taverns

The aim of this paper is to explore the nature of critical licensed house management skills within Bass Taverns. In particular, it focuses on the extent to which these are viewed as being concerned with 'soft' (behavioural) or 'hard' (technical) aspects of management. The focus of the research is on the 'shared understanding' of the importance of licensed house managerial skills. It is concerned with the identification of coherence and tensions in the criticality of certain managerial skills as perceived by the company's senior and licensed house managers. It presents the findings of surveys conducted at both senior and licensed house manager levels within the company to establish the extent to which interhierarchical consistency exists in the areas of critical skills/competences and whether these are seen as being specific to the organization or considered as generic. The research reports a general harmony regarding the nature of the skills required by licensed house managers and evidence of a focus on people-oriented skills, which are seen as being particularly important for achieving business success. Licensed house managers rated the critical skills as 'generic' rather than 'specific' to the taverns context, drawing attention to the need for the organization to address the manner in which these skills are developed.     

房价上涨、家庭债务与城镇居民消费:贷款价值比的视角

家庭借贷是缓解居民支大于收、平缓消费的重要手段，而贷款价值比的约束迫使家庭的债务规模必须控制在一定的范围之内；与此同时，持续上涨的房价不断逼近贷款价值比约束，最终表现为消费的大幅度波动。基于家庭追踪调查（CFPS）微观数据，本文细致考察了房价上涨、家庭债务对城镇居民消费的影响。结果表明：（1）家庭债务对城镇居民消费的杠杆显著，即使将样本细分为有房家庭与无房家庭，杠杆效应依然显著；（2）持续上涨的房价将显著促进有房家庭的消费，且这正向作用将被贷款价值比放大；而上涨的房价将抑制无房家庭的消费。（3）无论是有房家庭还是无房家庭，贷款价值比对居民消费的作用存在明显的门槛效应，即只有当贷款价值比增大到一定水平时，其对居民消费的影响将由促进转为抑制。（4）房价上涨对城镇居民消费的作用在不同群体间差异明显，受教育程度高的城镇家庭，或者持有二套房以上的家庭，房价上涨对城镇居民消费的促进效应更强。     

Human Interindividual Variability in Parameters Related to Health Risks

This paper reviews existing data on the variability in parameters relevant for health risk analyses. We cover both exposure-related parameters and parameters related to individual susceptibility to toxicity. The toxicity/susceptibility data base under construction is part of a longer term research effort to lay the groundwork for quantitative distributional analyses of non-cancer toxic risks. These data are broken down into a variety of parameter types that encompass different portions of the pathway from external exposure to the production of biological responses. The discrete steps in this pathway, as we now conceive them, are:Contact Rate (Breathing rates per body weight; fish consumption per body weight)Uptake or Absorption as a Fraction of Intake or Contact RateGeneral Systemic Availability Net of First Pass Elimination and Dilution via Distribution Volume (e.g., initial blood concentration per mg/kg of uptake)Systemic Elimination (half life or clearance)Active Site Concentration per Systemic Blood or Plasma ConcentrationPhysiological Parameter Change per Active Site Concentration (expressed as the dose required to make a given percentage change in different people, or the dose required to achieve some proportion of an individual's maximum response to the drug or toxicant)Functional Reserve Capacity–Change in Baseline Physiological Parameter Needed to Produce a Biological Response or Pass a Criterion of Abnormal FunctionComparison of the amounts of variability observed for the different parameter types suggests that appreciable variability is associated with the final step in the process–differences among people in functional reserve capacity. This has the implication that relevant information for estimating effective toxic susceptibility distributions may be gleaned by direct studies of the population distributions of key physiological parameters in people that are not exposed to the environmental and occupational toxicants that are thought to perturb those parameters. This is illustrated with some recent observations of the population distributions of Low Density Lipoprotein Cholesterol from the second and third National Health and Nutrition Examination Surveys.     

A subsidized reverse supply chain in the Chinese electronics industry

We study a special environmental producer responsibility policy for the Chinese electronics industry that is based on awarding a per unit subsidy to qualified returned electronic products and ensuring a minimum producer collection volume while allowing larger collection volumes. Based on a real application from a Chinese electronics company that produces LCD TVs, our paper studies the optimal design of the product’s reverse supply chain when there is flexibility in settling the inspection locations of the returned products and flexibility in the volume of returned products collected. The problem is modeled as a nonlinear mixed-integer program and an efficient outer approximation-based solution approach is proposed. Analytical results and extensive numerical experiments based on this real application are conducted. Observations novel to the reverse logistics literature are related to the testing location decisions (upstream or downstream) and the optimal collection volumes of returned products. Particularly, we show how the government can stimulate the collection amount of returned products by increasing the unit subsidy and we also find that the company’s marginal benefit from improving the subsidy increases in a superlinear fashion. Furthermore, the highest collection volumes may not occur at the highest quality level of returned products for capacitated remanufacturers. The company can also be incentivized to increase the collection of returned products by permitting flexible testing locations. We also observe how the optimal testing locations vary for different levels of unit subsidy and different ratios of qualified and non-qualified returned products. Finally, conclusions and future research directions are provided.     

权证发行对标的资产交易行为的影响研究

本文用事件研究方法分析了内陆认股权证上市对标的股价和交易量的影响.检验上市交易的总体认股权证样本,发现权证上市后短时期内股价下降和交易量增加;可创设权证的标的资产价格和交易量在发行后短时期内上升.原因可认为权证上市向市场传递了一个利空信息,导致股价在权证上市前大幅下跌;其次卖空限制使股价下降风险得不到有效规避;最后市场规章制度的变化也是其中原因.异常收益检验结果证明内陆资本市场是不完全的.     

Residential Air Exchange Rates in the United States: Empirical and Estimated Parametric Distributions by Season and Climatic Region

The purpose of this paper is to undertake a statistical analysis to specify empirical distributions and to estimate univariate parametric probability distributions for air exchange rates for residential structures in the United States. To achieve this goal, we used data compiled by the Brookhaven National Laboratory using a method known as the perfluorocarbon tracer (PFT) technique. While these data are not fully representative of all areas of the country or all housing types, they are judged to be by far the best available. The analysis is characterized by four key points: the use of data for 2,844 households; a four-region breakdown based on heating degree days, a best available measure of climatic factors affecting air exchange rates; estimation of lognormal distributions as well as provision of empirical (frequency) distributions; and provision of these distributions for all of the data, for the data segmented by the four regions, for the data segmented by the four seasons, and for the data segmented by a 16 region by season breakdown. Except in a few cases, primarily for small sample sizes, air exchange rates were found to be well fit by lognormal distributions (adjusted R² 0.95). The empirical or lognormal distributions may be used in indoor air models or as input variables for probabilistic human health risk assessments.     

The Effect of Learning and Integration Investment on Manufacturing Outsourcing Decisions: A Game Theoretic Approach

We introduce a two‐period Stackelberg game of a supplier and buyer. We recognize that learning from manufacturing experience has many advantages. Consistent with the literature, we assume both the buyer and supplier realize reductions in their respective production costs in period 2 due to volume‐based learning from period 1 production. In addition, we introduce another learning concept, the future value, to capture the buyer's benefits of transferring current manufacturing experience for the design and development of future products and technologies. In contrast to the literature, we allow the supplier two mechanisms to impact the buyer's outsourcing decision: price and the investment in integration process improvement (IPI) that reduces the buyer's unit cost of integration. IPI may include the investment in new materials, specialized technology, or the re‐design of the integration process. Conditions are given whereby the buyer partially outsources component demand as opposed to fully outsourcing or fully producing in‐house. Furthermore, conditions are given characterizing when the supplier's price and investment in IPI are substitute strategies versus complements. Both analytic and numerical results are presented.     

中国区域房地产价格异质收敛与调控政策研究

通过研究区域房价的异质收敛为实施区域差异化房地产市场调控提供政策依据.采用非线性时变因子模型对全国30个省市自治区2001M1~2013M12的房价进行实证得出,传统的经济或行政区域划分对区域房地产市场不适用,中国区域房地产价格存在异质收敛,可划分为3个收敛子群.地理因素或经济因素不是区域房价收敛的主导因素,重要的房地产调控政策能够本质性地改变区域房价的收敛情况,而且这种作用一般生效于政策发布后的4~5个月.     

基于XBRL的财务信息标准博弈分析

运用两阶段斯塔克伯格博弈模型研究了XBRL在利益相关者之间的扩散问题,分析了XBRL技术标准的采用对主体企业和利益相关者交易价格、交易量、市场份额以及利润的影响。结果表明:当部分利益相关者采用XBRL时,主体企业的总交易量变大;对采用者来说,交易价格变高,交易量变大,市场份额增大,当采用者数量较少时利润减少,而当采用者数量足够多时利润增加;对未采用者来说,交易价格变低,交易量变小,市场份额缩小,利润总额降低。对主体企业来说,部分采用而不是所有利益相关者都采用XBRL技术标准才是最佳结果,也就是存在最优的采用者数量使得主体企业在XBRL技术扩散中获得最大利润。     

Use of Markov Chain Monte Carlo Analysis with a Physiologically-Based Pharmacokinetic Model of Methylmercury to Estimate Exposures in U.S. Women of Childbearing Age

A Bayesian approach, implemented using Markov Chain Monte Carlo (MCMC) analysis, was applied with a physiologically‐based pharmacokinetic (PBPK) model of methylmercury (MeHg) to evaluate the variability of MeHg exposure in women of childbearing age in the U.S. population. The analysis made use of the newly available National Health and Nutrition Survey (NHANES) blood and hair mercury concentration data for women of age 16–49 years (sample size, 1,582). Bayesian analysis was performed to estimate the population variability in MeHg exposure (daily ingestion rate) implied by the variation in blood and hair concentrations of mercury in the NHANES database. The measured variability in the NHANES blood and hair data represents the result of a process that includes interindividual variation in exposure to MeHg and interindividual variation in the pharmacokinetics (distribution, clearance) of MeHg. The PBPK model includes a number of pharmacokinetic parameters (e.g., tissue volumes, partition coefficients, rate constants for metabolism and elimination) that can vary from individual to individual within the subpopulation of interest. Using MCMC analysis, it was possible to combine prior distributions of the PBPK model parameters with the NHANES blood and hair data, as well as with kinetic data from controlled human exposures to MeHg, to derive posterior distributions that refine the estimates of both the population exposure distribution and the pharmacokinetic parameters. In general, based on the populations surveyed by NHANES, the results of the MCMC analysis indicate that a small fraction, less than 1%, of the U.S. population of women of childbearing age may have mercury exposures greater than the EPA RfD for MeHg of 0.1 μg/kgg/day, and that there are few, if any, exposures greater than the ATSDR MRL of 0.3 μgg/kgg/day. The analysis also indicates that typical exposures may be greater than previously estimated from food consumption surveys, but that the variability in exposure within the population of U.S. women of childbearing age may be less than previously assumed.     

On the Solution Approach for Bayesian Modeling of Initiating Event Frequencies and Failure Rates

There is a need for plant-specific distributions of incidence and failure rates rather than distributions from pooled data which are based on the "common incidence rate" assumption. The so-called superpopulation model satisfies this need through a practically appealing approach that accounts for the variability over the population of plants. Unfortunately, the chosen order in which the integrals with respect to the individual plant rates λ_i, ( i = 0, 1…, m ) and the parameters a , β of the Γ-population distribution are solved seems to drive the solution close to the common incidence rate distribution. It is shown that the solution obtained from interchanging the order and solving the integrals with respect to the individual plant rates by Monte Carlo simulation very quickly provides the plant specific distribution. This differing solution behaviour may be due to the lack of uniform convergence over (α, β, λ_I, ( i = 1,…, m ))-space. Examples illustrate the difference that may be observed.     

Stackelberg竞争下考虑消费者转移和平台差异的供应商运营策略

考虑消费者转移和平台差异对需求的影响,构建不同渠道结构和销售契约下的决策模型;基于水平和垂直Stackelberg博弈,获得8种情形下的最优决策。探究佣金率、平台差异和消费者转移率对均衡结果的影响,获得最优的销售契约和渠道配置策略。研究表明:代理模式可以降低产品的销售价格,提升销量;垄断市场中,平台更愿意采取转售模式,而供应商更偏好代理模式;竞争环境下,优势平台一定条件下总是更偏好转售模式,而竞争平台销售模式偏好随着佣金率逐渐变化;供应商的渠道选择与消费者转移量有关,当转移量较高时,供应商偏向双渠道结构,反之亦然。     

Evaluation of the Uncertainty in an Oral Reference Dose for Methylmercury Due to Interindividual Variability in Pharmacokinetics

An analysis of the uncertainty in guidelines for the ingestion of methylmercury (MeHg) due to human pharmacokinetic variability was conducted using a physiologically based pharmacokinetic (PBPK) model that describes MeHg kinetics in the pregnant human and fetus. Two alternative derivations of an ingestion guideline for MeHg were considered: the U.S. Environmental Protection Agency reference dose (RfD) of 0.1 g/kg/day derived from studies of an Iraqi grain poisoning episode, and the Agency for Toxic Substances and Disease Registry chronic oral minimal risk level (MRL) of 0.5 g/kg/day based on studies of a fish-eating population in the Seychelles Islands. Calculation of an ingestion guideline for MeHg from either of these epidemiological studies requires calculation of a dose conversion factor (DCF) relating a hair mercury concentration to a chronic MeHg ingestion rate. To evaluate the uncertainty in this DCF across the population of U.S. women of child-bearing age, Monte Carlo analyses were performed in which distributions for each of the parameters in the PBPK model were randomly sampled 1000 times. The 1st and 5th percentiles of the resulting distribution of DCFs were a factor of 1.8 and 1.5 below the median, respectively. This estimate of variability is consistent with, but somewhat less than, previous analyses performed with empirical, one-compartment pharmacokinetic models. The use of a consistent factor in both guidelines of 1.5 for pharmacokinetic variability in the DCF, and keeping all other aspects of the derivations unchanged, would result in an RfD of 0.2 g/kg/day and an MRL of 0.3 g/kg/day.     

Are People Willing to Buy Natural Disaster Insurance in China? Risk Awareness,Insurance Acceptance,and Willingness to Pay

After the Wenchuan earthquake (magnitude 7.9, May 12, 2008), intensive debates on how China should establish a natural disaster insurance system were initiated among researchers, policymakers, and insurance professionals. Our focus was the social aspects of disaster insurance, explored in China through a nationwide survey. Our questionnaires investigated people's risk awareness, insurance acceptance, their opinions on governmental measures for disaster management, and their willingness to pay for disaster house insurance. We analyzed the results at both regional and individual scales. We found that the integrated hazard index and respondents’ experience of insurance (considered objective factors), and their opinions on the importance of insurance and government responsibility (considered subjective factors) showed strong correlation with the regional overall acceptance of disaster insurance. An individual's decision to participate highly depended on his/her experience of both insurance and disaster and his/her opinion on the importance of insurance as a coping mechanism. Respondents from poverty‐stricken or less‐developed counties were not necessarily more reluctant to accept natural disaster insurance, though they exhibited relatively lower ability to afford insurance. In general, respondents had correct perceptions of natural disasters in their areas; however, people from regions with a greater multihazard threat showed less willingness to accept disaster insurance because they tended to expect the government to undertake to cover losses and considered insurance to be less important. People's willingness to pay for an assumed disaster house insurance was also investigated and analyzed. We consequently discuss the policy implications for developing a disaster insurance system in China.     

Challenges to the Acceptance of Probabilistic Risk Analysis

This paper discusses a number of the key challenges to the acceptance and application of probabilistic risk analysis (PRA). Those challenges include: (a) the extensive reliance on subjective judgment in PRA, requiring the development of guidance for the use of PRA in risk-informed regulation, and possibly the development of robust or reference prior distributions to minimize the reliance on judgment; and (b) the treatment of human performance in PRA, including not only human error per se but also management and organizational factors more broadly. All of these areas are seen as presenting interesting research challenges at the interface between engineering and other disciplines.     

Physiologically Based Pharmacokinetic Models in Developmental Toxicology

The kinetics of disposition of drugs and environmental chemicals will be altered as a result of the rapid and pronounced anatomic and physiologic changes that occur during pregnancy. These include changes in maternal intestinal motility, pulmonary tidal volume and minute volume, cardiac output, and renal function as well as in maternal tissue and fluid volumes and in the weight of the embryo/fetus and its developing organs. Physiologically-based models of pregnancy are capable of taking these temporal changes into account. Several such models have been developed. They vary in their characteristics, depending on the chemical under consideration and the period of gestation of concern to the developers of the models. Several physiologically-based models of gestation are outlined, and an example is given of the application of a physiologically-based model of gestation to predict dose to the rat and mouse fetus.