GMM Estimation with persistent panel data: an application to production functions

This paper considers the estimation of Cobb-Douglas production functions using panel data covering a large sample of companies observed for a small number of time periods. GMM estimatorshave been found to produce large finite-sample biases when using the standard first-differenced estimator. These biases can be dramatically reduced by exploiting reasonable stationarity restrictions on the initial conditions process. Using data for a panel of R&Dperforming US manufacturing companies we find that the additional instruments used in our extended GMM estimator yield much more reasonable parameter estimates.     

Classroom sex composition and first-grade school outcomes: The role of classroom behavior

Using nationally representative data from the Early Childhood Longitudinal Study-Kindergarten Cohort (N = 21,409; 10,452 girls and 10,957 boys; mean age = 7.24 years), the association between first-grade classroom sex composition (CSC), measured as the percentage of female students, and end of the year academic (reading, mathematics) and socio-emotional (externalizing problems, internalizing problems, self-control, interpersonal skills) outcomes was examined. Using multilevel modeling techniques and controlling for prior achievement levels, CSC was positively associated with children’s reading achievement at the end of first grade; students performed better in reading in classes with a higher percentage of female students. CSC was also associated with three of the socio-emotional outcomes; controlling for prior levels, students in classrooms with a higher percentage of girls had better self-control and interpersonal skills and fewer internalizing problems. Classroom behavior mediated the effects of CSC on reading achievement and the socio-emotional outcomes. Implications for the composition of first-grade classrooms are discussed.     

Residualization is not the answer: Rethinking how to address multicollinearity

Here I show that a commonly used procedure to address problems stemming from collinearity and multicollinearity among independent variables in regression analysis, “residualization”, leads to biased coefficient and standard error estimates and does not address the fundamental problem of collinearity, which is a lack of information. I demonstrate this using visual representations of collinearity, hypothetical experimental designs, and analyses of both artificial and real world data. I conclude by noting the importance of examining methodological practices to ensure that their validity can be established based on rational criteria.     

Child maltreatment and foster care

In “Child Maltreatment and Foster Care,” Richard J. Gelles, a professor at the University of Pennsylvania School of Social Work, reports what is known about the incidence of child maltreatment and foster care placement rates since welfare reform. He relies on four major sources of data: Current Trends in Child Abuse Reporting and Fatalities: Results of the 1998 Annual Fifty State Survey, the National Child Abuse and Neglect Data System (NCANDS), the National Incidence Survey of Reported and Recognized Child Maltreatment (NIS), and the Voluntary Cooperative Information System (VCIS).     

《欧洲思想起源》导论

从古希腊早期哲学家话语研究欧洲思想的起源是不够的,那是传统大树上的枝杈而非根脉。荷马史诗在某种程度上呈现出最早的希腊人的真实历史样貌,其中充满着后世文明人难以理解的野蛮因素。有关神话与传说的知识是重建文明发生过程的主要素材,是将石器时代与文明时代相连接的认知通道。《伊里亚特》《奥德赛》所透露的生活方式和思维方式像一座永久的历史记忆之丰碑,是我们现在所掌握的最早描写欧洲的生活和思想的活的教材。     

中国古代管理哲学与西方现代管理理论的差异及互鉴

中国古代管理哲学与西方现代管理理论的差异和优劣势主要体现在管理的基本价值观、基本思维方式、管理主体和客体、主要目标、权力基础、基本管理方式以及管理创新特征等方面。双方相互借鉴的主要方向是：中国应借鉴西方保护个体利益并重视公平竞争和激励、追求标准化的科学管理、强调经济效益和效率、强调民主与“法治”、鼓励创新并保护创新成果等思想中的合理成分,以及西方在领导理论和工商管理领域的有益成果;西方应借鉴中国的人本论、整体观、系统观和权变观、“中庸之道”、“修己安人”、“和为贵”、世界“大同”、民本论、“道治”、“德治”和“智治”等管理思想中的合理成分,以及在伦理管理、国家管理和军事管理等领域的有益成果。     

A cyclical view of the relationship between corporate governance and strategic management

The vast majority of research on the relationship between corporate governance and strategic management focuses on the impact of corporate governance on strategic management. In this article we propose a cyclical model, highlighting that strategic decisions can also affect corporate governance through shaping firm ownership structure. We discuss the impacts of strategic decisions on firm ownership structure and corporate governance in the contexts of publicly traded firms, private firms, and the privatization of state-owned enterprises. We hope that our cyclical model can promote researchers to develop a more complete view about the relationships between strategic management, ownership structure, and corporate governance.     

A Comparative Pharmacokinetic Estimate of Mercury in U.S. Infants Following Yearly Exposures to Inactivated Influenza Vaccines Containing Thimerosal

The use of thimerosal preservative in childhood vaccines has been largely eliminated over the past decade in the United States because vaccines have been reformulated in single‐dose vials that do not require preservative. An exception is the inactivated influenza vaccines, which are formulated in both multidose vials requiring preservative and preservative‐free single‐dose vials. As part of an ongoing evaluation by USFDA of the safety of biologics throughout their lifecycle, the infant body burden of mercury following scheduled exposures to thimerosal preservative in inactivated influenza vaccines in the United States was estimated and compared to the infant body burden of mercury following daily exposures to dietary methylmercury at the reference dose established by the USEPA. Body burdens were estimated using kinetic parameters derived from experiments conducted in infant monkeys that were exposed episodically to thimerosal or MeHg at identical doses. We found that the body burden of mercury (AUC) in infants (including low birth weight) over the first 4.5 years of life following yearly exposures to thimerosal was two orders of magnitude lower than that estimated for exposures to the lowest regulatory threshold for MeHg over the same time period. In addition, peak body burdens of mercury following episodic exposures to thimerosal in this worst‐case analysis did not exceed the corresponding safe body burden of mercury from methylmercury at any time, even for low‐birth‐weight infants. Our pharmacokinetic analysis supports the acknowledged safety of thimerosal when used as a preservative at current levels in certain multidose infant vaccines in the United States.