Reinforced structural holes

Holes in social structure are variably reinforced by the social organization around the hole. The more reinforced the hole, the greater the difficulty in bridging it, but the more likely a successful bridge will carry information novel, and so potentially valuable, to people on the other side. To study how reinforcement varies with access to structural holes, and the achievement associated with access, I propose a measure of access to reinforced structural holes (RSH), and present results predicting achievement in an integrated banker organization and a balkanized supply-chain organization. In both study populations, the people who have access to structural holes also have access to reinforced structural holes, and all measures of access have a statistically significant association with achievement. However, there is no consistent prediction advantage from incorporating reinforcement in measures of access to structural holes. The reinforced-holes measure predicts compensation better or as well as network constraint and betweenness, but is weaker or no better than a count of nonredundant contacts. I do not infer from the results a rank-order of alternative measures so much as substitutability. I expect achievement to be associated with access to structural holes, but I expect the association to vary across alternative measures depending on how achievement is achieved in a specific population.     

品牌、认证与消费者信任倾向——以有机牛奶为例

以山东省570个消费者样本为例,基于中欧比较视角,探究消费者对不同品牌或认证的有机牛奶的信任倾向,并运用结构方程模型分析了消费者信任的前因。结果表明,消费者个体特征、感知价值、有机食品知识及行业环境对消费者信任产生显著正向影响,而食品安全意识和信息交流对信任的影响较为复杂;消费者对中欧品牌或中欧认证的信任存在差异,形成前因也略有不同。提升公众消费信心,应着力于推动有机知识宣传普及、增加消费者体验以及强化行业监管,乳品企业应根据消费者中外品牌或认证信任的差异制定相应的营销策略。     

Comparing two measures of creatinine clearance: an application of errors-in-variables and bootstrap techniques

Two indices of creatinine clearance (an index of kidney function) are compared on a group of cancer patients who underwent chemotherapy with a potentially nephrotoxic drug. The standard index, measured creatinine clearance MCC, is cumbersome to use, whereas the more convenient alternative, estimated creatinine clearance ECC, has not yet been conclusively evaluated on cancer patients. We conclude that under certain clinical conditions ECC and MCC are identically calibrated for males, but not for females, and we obtain estimated true and false positive rates for assessing the use of ECC instead of MCC as a diagnostic tool. We use a model that is formally equivalent to an errors-in-variables model with (unbalanced) repeated observations and correlated measurement errors. The bootstrap is used to obtain standard errors and confidence limits.     

An Exploratory Analysis of the Value of the Skills of IT Personnel: Their Relationship to IS Infrastructure and Competitive Advantage

Determining and assessing the requisite skills of information technology (IT) personnel have become critical as the value of IT has risen in modern organizations. In addition to technical skills traditionally expected of IT personnel, softer skills like managerial, business, and interpersonal skills have been increasingly cited in previous studies as mandatory for these employees. This paper uses a typology of IT personnel skills—technology management skills, business functional skills, interpersonal skills, and technical skills—and investigates their relationships to two information systems (IS) success variables, IS infrastructure flexibility and the competitive advantage provided by IS. The study investigates these relationships using the perceptions of chief information officers (CIOs) from mostly Fortune 2000 companies. The contributions of this study are: IT personnel skills do affect IS success, technical skills are viewed as the most important skill set in affecting IS infrastructure flexibility and competitive advantage, and modularity is viewed as more valuable to competitive advantage than integration. Several explanations are offered for the lack of positive relationships between the softer IT personnel skills and the dimensions of IS success used in this study.     

投资品相对价格、技术冲击与劳动要素投入——基于RBC观点的一个实证研究

本文由实证层面详细地考察了中性的与投资技术冲击对于我国劳动就业的宏观动态影响.基于投资品相对价格的长期趋势特征,我们发现:在长期限制识别条件下,正向的投资(中性)技术冲击对于劳动就业具有明显的促进作用(负向的抑制效应).这意味着,仅考虑单一中性技术冲击的SVAR模型混淆了不同性质的技术冲击对于劳动就业的不同影响.     

Instrumental Variable Estimation of Nonparametric Models

In econometrics there are many occasions where knowledge of the structural relationship among dependent variables is required to answer questions of interest. This paper gives identification and estimation results for nonparametric conditional moment restrictions. We characterize identification of structural functions as completeness of certain conditional distributions, and give sufficient identification conditions for exponential families and discrete variables. We also give a consistent, nonparametric estimator of the structural function. The estimator is nonparametric two‐stage least squares based on series approximation, which overcomes an ill‐posed inverse problem by placing bounds on integrals of higher‐order derivatives.     

结构转变、制度变迁下的人口红利与经济增长

已有的对人口红利影响经济增长的实证研究未将结构和制度的重大变革纳入模型,这与东亚及我国经济增长的现实不符。本文通过在模型中纳入结构转变和制度变迁变量,用1978～2008年的数据进行误差修正分析,计算出在结构转变和制度变迁的背景下,我国人口红利及各要素对经济增长的影响。结果发现,固定资产投资对我国经济增长的影响程度最大,其次是技术进步,第三是制度变迁,结构变化的影响也很显著。人口红利的影响也较显著,但是其对经济增长解释力度较小。因此随着人口红利的逐渐消失,未来的经济增长更需要依靠投资、技术进步、结构变迁和制度变革。     

Interorganizational Determinants of Environmental Purchasing: Initial Evidence from the Consumer Products Industries*

Environmental purchasing consists of the purchasing function's involvement in activities that include reduction, recycling, reuse, and substitution of materials. Despite the potentially important role that the purchasing function can play in a firm's environmental activities, little research has been performed to date that examines the factors that impact environmental purchasing. The authors develop and empirically test a theoretical model that examines how interorganizational factors both drive and constrain purchasing's involvement in environmental activities. The empirical findings suggest that environmental purchasing activities will be facilitated through increased coordination with suppliers as well as downstream members of the supply chain, including retailers. The results also suggest the need for increased coordination within the firm, particularly between the purchasing function on the inbound side and marketing and distribution functions on the outbound side.     

Causal Linkages in Supply Chain Management: An Exploratory Study of North American Manufacturing Firms

In this paper we investigate the key causal linkages in supply chain management. We propose a conceptual framework and test this framework on data from 215 North American manufacturing firms using structural equation modeling techniques. Three major research issues are addressed in this study: Do sourcing decisions affect the degree to which firms achieve manufacturing goals of cost, flexibility, dependability, and quality? Does the degree of manufacturing goal achievement lead to higher customer responsiveness? Does the degree of manufacturing goal achievement lead to higher internal manufacturing performance? The study examines the relationship among sourcing decisions, manufacturing goals, customer responsiveness, and manufacturing performance. The results support the notion that an integrated supply chain involves aligning sourcing decisions to achieve manufacturing goals that are set to respond favorably to the needs of customers.     

A Bayesian analysis on time series structural equation models

Structural equation models (SEM) have been extensively used in behavioral, social, and psychological research to model relations between the latent variables and the observations. Most software packages for the fitting of SEM rely on frequentist methods. Traditional models and software are not appropriate for analysis of the dependent observations such as time-series data. In this study, a structural equation model with a time series feature is introduced. A Bayesian approach is used to solve the model with the aid of the Markov chain Monte Carlo method. Bayesian inferences as well as prediction with the proposed time series structural equation model can also reveal certain unobserved relationships among the observations. The approach is successfully employed using real Asian, American and European stock return data.