Generalized Linear Latent Variable Modeling for Multi-Group Studies

ABSTRACT

Latent variable modeling is commonly used in behavioral, social, and medical science research. The models used in such analysis relate all observed variables to latent common factors. In many applications, the observations are highly non normal or discrete, e.g., polytomous responses or counts. The existing approaches for non normal observations can be considered lacking in several aspects, especially for multi-group samples situations. We propose a generalized linear model approach for multi-sample latent variable analysis that can handle a broad class of non normal and discrete observations, and that furnishes meaningful interpretation and inference in multi-group studies through maximum likelihood analysis. A Monte Carlo EM algorithm is proposed for parameter estimation. The convergence assessment and standard error estimation is addressed. Simulation studies are reported to show the usefulness of the our approach. An example from a substance abuse prevention study is also presented.     

Nonlinear Regression

It is often thought that regression data should be mean-centered before being diagnosed for collinearity (ill conditioning). This view is shown not generally to be correct. Such centering can mask elements of ill conditioning and produce meaningless and misleading collinearity diagnostics. In order to assess conditioning meaningfully, the data must be in a form that possesses structural interpretability.     

Preventing Domestic Violence by Changing Australian Gender Relations: Issues and Considerations

ABSTRACT

In recent years Australian governments have significantly refocused domestic violence policies to prioritise primary prevention strategies. The objective of such strategies is to change how Australians perceive, acknowledge, and respond to domestic violence as a gender-based problem. Recognising the value of these efforts to address oppressive cultural practices, we draw attention to limitations inherent in shifting culture as a means to prevent domestic violence. We demonstrate how governments may improve policy approaches by addressing the structural inequalities that have historically forced women into positions of subordination. This will help us move toward more effective and long-term solutions to domestic violence.

IMPLICATIONS

• Australian domestic violence policy must include structural and systems changes prioritising women’s equal rights in addition to equal opportunities.

• To change cultural attitudes and behaviours, we must alter the environment in which oppressions and opportunities are located.

• Social workers can shape the debate to ensure that changing culture to prevent domestic violence is conceptualised as part of a wider social and policy change agenda.

     

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.     

中国省际农业生产力成长差异及其结构性因素

近几年,由于政策推动等多方面因素作用,中国农业连续五年实现粮食大幅增产,结构性调整也正逐步推进。但多年来,要素投入而非技术进步是支撑中国农业增长的根本要素这一状况并未得以根本改变。通过测度省际间农业生产力成长水平可见,技术退步是造成近年来中国农业生产力趋于下降的根本原因。另一方面,定量考察影响农业生产力变动的结构性因素时发现,部分旨在提升农业生产力水平的政策,从实际效果来看并未能够达成政策的初衷,有必要做出适当修正。     

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。