Diversification,Performance, and the Corporate Life Cycle

This paper investigates the relation between the extent of diversification in firms and their performance at different life cycle stages. To illustrate the joint endogeneity of diversification and performance, we treat both the extent of diversification and firm performance as endogenous variables in a simultaneous equation system. Empirical results reveal that corporate diversification erodes firm value. Overall, firms in their growing stages experience a significant diversification discount; however, mature firms do not show such findings. Although unrelated diversification leads to trading at a discount in all growing and mature firms, conversely, related diversification exhibits an evident premium in mature firms.     

Lone Mothers: What is to be done?

This Dialogue presents the views of four authors, from the US, the UK, and Norway, on the best policies to help lone mothers. Lone mothers face an inevitable dilemma in allocating their time between earning income and caring for their children. The low-earning capacity of women in an unequal labor market exacerbates the problem, causing material hardship for many lone mothers and their families. The policy solutions proposed lie along a spectrum, ranging from those that seek to enable all lone mothers to take employment to those that aim to let mothers choose whether to take employment or care for their children themselves. Other policies discussed concern ways to value and support caregiving, improve the low-wage labor market for women, and provide a set of income supports that would both boost income and provide time to care for children.     

浅析新课程背景下的生活化课堂教学

生活化课堂教学是新课程背景下提出来的一种新的教学理念和教学模式。它的基本特征是日常教学生活化、课堂教学现实化、课堂生活可能化。基于新课程理念的生活化课堂教学体系的建构策略主要包括教学目标要基于生活、教学内容要回归学生的生活世界、教学过程要注重自然生成、教学模式要寓于生活。     

Risk factors associated with life jacket wear among adult canoeists and kayakers in the United States, 1999–2017

Abstract

Drowning is the most common cause of death in recreational boating. Life jackets prevent drowning, yet adult wear rates remain relatively low on most types of boats. Canoes and kayaks are among the least used boat types, yet maintain the third and first highest annual boating-related drowning rates in 2012, respectively. This 1999–2017 study collected data from 124 study sites across the US. Life jacket wear was calculated for 13 dichotomized risky and non-risky variables, using Chi-square tests. A count variable based on number of risks was created, and Cochran-Armitage trend tests examined linearity in life jacket use. Three illustrative variables for each boat type were represented in tree diagrams. Kayakers had higher wear rates than canoeists among all variables observed. For both boats, the majority of risky conditions had higher life jacket wear rates than their non-risky alternatives. As the number of risks increased, life jacket wear rate increased. Boaters seemingly conduct a mental assessment of risk to determine whether to wear a life jacket.     

效用理论在飞行安全风险评估中的应用

为科学划分飞行安全风险等级,将效用理论引入飞行安全风险领域,利用效用函数,建立了飞行安全风险评估模型。在分析飞行安全风险的基础上,通过定义事故或危险事件损失效应,选取合适的效用函数进行飞行安全风险的度量。模型有效区分了类似飞行事故这样高损失、低概率事件与飞行事故征候这样低损失、高概率事件风险之间的差异,克服了期望值法的局限性。最后通过实例验证了该方法的科学性和有效性。     

Progression,Stability, or Decline? Sociological Mechanisms Underlying Change in Specialization Among Birdwatchers

Using a panel of American birdwatchers collected in 1997 and 2002, we tested the extent to which birdwatchers progressed over a five-year period. The impact different career contingencies and life course events had on predicting change in birdwatchers' behavior, skill, and commitment was also examined. Findings indicated that although progression characterized some birdwatchers' participation, involvement by others was better characterized by stability or decline, which was true for each of the indicators used to measure specialization. Career contingencies and life course changes had only a moderate influence on predicting change in the specialization indicators over time. Support from family members and retirement were the best predictors of change in specialization.     

山村教师作文教学心得

做了多年山村语文教师,深深地知道乡下学生写作时难以突破的瓶颈是:因为山村的闭塞,见不多识不广,写作套路明白,但脑子空空如也。尤其是写议论文,明明有了很好的论点,可苦于没有典型的论据,关键时刻不得不临时改换内容,或者七拼八凑地编写。这样的文章内容空洞、干瘪是自然的,分数不高也在情理之中。突破这个瓶颈的办法是恶补典型材料。但时间有限,精力有限,怎么恶补才见效呢?我的做法是利用现有条件,教学生学好课文用好课文。     

Remark on a theorem by Gurland

Abstract

Let X ₁,X ₂,...,X _n be a random sample of size from a distribution with probability density function p(x|θ), where the unknown parameter θ belongs to a non-degenerate interval I. The unknown true value of θ will be denoted by θ₀.     

Explaining organizational responsiveness to work‐life balance issues: The role of business strategy and high‐performance work systems

This article applies new insights into business strategies and high‐performance work systems (HPWSs) to examine why organizations adopt work‐life balance programs (WLBPs). Results indicate that a product leadership business strategy is positively related to the likelihood of adopting WLBPs, whereas a cost leadership business strategy is negatively related to the adoption of these programs. Moreover, our analyses establish a mediating role of HPWSs in the relationship between business strategies and the adoption of WLBPs. Our results also demonstrate that different industries vary in adoption of work‐life balance programs. This supports the institutional theory of organizational responsiveness to work‐life balance issues. We tested our hypotheses with two waves of the nationally representative Canadian Workplace and Employee Survey. Implications and specific suggestions for human resource practitioners are discussed. © 2012 Wiley Periodicals, Inc.     

Assessing the role of components of life satisfaction

Factors affecting subjective well-being and their gross effect measurement have been widely studied. However, how people derive utility from these factors has not been fully explored. This article provides a way to decompose the gross effect of major determinants on life satisfaction into direct and indirect effects and make inference for the latter. Because the indirect effect is nonlinear in parameters associated with different models in an equation system, it creates a problem in estimating the standard error. Besides, the categorical nature in survey data further introduces bias to the covariance estimation even asymptotically. To address these issues without knowing the form of heteroskedasticity under the null hypothesis, we propose to extend the wild bootstrap procedure in this particular context. Its robustness against various data properties is validated via several simulation experiments. Using three recent waves of World Values Survey, we find that the relative importance of life control has significantly increased recently, and endowing citizens with the right to enjoy their freedoms and liberties is a more effective policy in raising life satisfaction than promoting national income.