第一大股东持股和公司价值:激励效应和防御效应

本文以上海证券交易所的A股上市公司2003年和2004年的横截面数据为基础,计量了第一大股东持股与公司价值之间的经验关系,并考察了第一大股东持股对公司价值影响的区间特征.作者观察到,第一大股东对公司价值同时存在激励效应和防御效应,第一大股东持股与公司价值之间存在显著的三次非线性曲线关系.     

非财务指标评价企业业绩分析

企业经营业绩,其表现形式是多方面的,通常用一系列相互联系的财务指标来描述。但若仅以财务指标来评价企业的经营业绩是不全面和不公正的,不符合当今信息时代的要求。信息时代已不同于工业时代,它以知识经济与创新、一体化、全球化和个体化为特征,市场竞争空前激烈。所以还必须设立有关业绩评价的非财务指标,把财务指标评价与非财务指标评价结合起来。     

Leveraging risk assessment for foodborne outbreak investigations: The Quantitative Risk Assessment-Epidemic Curve Prediction Model

Root cause analysis can be used in foodborne illness outbreak investigations to determine the underlying causes of an outbreak and to help identify actions that could be taken to prevent future outbreaks. We developed a new tool, the Quantitative Risk Assessment-Epidemic Curve Prediction Model (QRA-EC), to assist with these goals and applied it to a case study to investigate and illustrate the utility of leveraging quantitative risk assessment to provide unique insights for foodborne illness outbreak root cause analysis. We used a 2019 Salmonella outbreak linked to melons as a case study to demonstrate the utility of this model (Centers for Disease Control and Prevention [CDC], 2019). The model was used to evaluate the impact of various root cause hypotheses (representing different contamination sources and food safety system failures in the melon supply chain) on the predicted number and timeline of illnesses. The predicted number of illnesses varied by contamination source and was strongly impacted by the prevalence and level of Salmonella contamination on the surface/inside of whole melons and inside contamination niches on equipment surfaces. The timeline of illnesses was most strongly impacted by equipment sanitation efficacy for contamination niches. Evaluations of a wide range of scenarios representing various potential root causes enabled us to identify which hypotheses, were likely to result in an outbreak of similar size and illness timeline to the 2019 Salmonella melon outbreak. The QRA-EC framework can be adapted to accommodate any food–pathogen pairs to provide insights for foodborne outbreak investigations.     

Longitudinal links of parental solicitation,knowledge, and peer approval with deviance during early adolescence

The current study examined growth-to-growth associations of parental solicitation, knowledge, and peer approval with deviance during early adolescence, using a 4-wave, 18-month self-reported longitudinal data set from 570 Czech early adolescents (58.4% female; M_age = 12.43 years, SD = 0.66 at baseline). Unconditional growth model tests provided evidence of significant changes in the three parenting behaviors and in deviance over time. Multivariate growth model tests showed that declines in maternal knowledge were associated with increases in deviance, while greater increases in parental peer approval were associated with slower increases in deviance. Findings provide evidence of dynamic changes in parental solicitation, knowledge, and peer approval over time, as well as in deviance; additionally, they importantly show how parental knowledge and peer approval covary developmentally with deviance.     

Estimation When a Parameter is on a Boundary

This paper establishes the asymptotic distribution of an extremum estimator when the true parameter lies on the boundary of the parameter space. The boundary may be linear, curved, and/or kinked. Typically the asymptotic distribution is a function of a multivariate normal distribution in models without stochastic trends and a function of a multivariate Brownian motion in models with stochastic trends. The results apply to a wide variety of estimators and models. Examples treated in the paper are: (i) quasi-ML estimation of a random coefficients regression model with some coefficient variances equal to zero and (ii) LS estimation of an augmented Dickey-Fuller regression with unit root and time trend parameters on the boundary of the parameter space.     

求y″ py′ qy=f(x)特解的一种新方法

对于二阶常系数非齐次线性微分方程：ｙ″＋ ｐｙ′＋ ｑｙ＝ ｆ（ｘ），给出了当特征根ｒ１ 与ｒ２不等时的特解公式。利用该公式，只需求出两个一阶线性微分方程的特解，就可以得到相应二阶常系数非齐次线性微分方程的特解。     

Special issue: Child protection in the digital age. Latent profiles in cyberbullying and the relationship with self-concept and achievement goals in preadolescence

In recent years, the scientific community has taken an interest in cyberbullying research due to the emotional and educational impact on all those involved. However, the scant evidence on samples from primary education is derived from statistical methodologies focusing on the individual, which generate specific profiles rather than acting roles. The present study focuses on the profiles of cyberbullying and its variability with the levels of self-concept and academic goals, using a sample of 548 Spanish primary education students aged 10–13 (M = 10.95, SD = 0.7). After analysing the data using Latent Class Analysis and MANOVA, the profiles developed were ‘not-involved’ (38.82%), ‘moderate victimization’ (37.17%), ‘high bully-victimization’ (19.29%) and ‘low victimization’ (4.7%). In addition, the group of students with the not-involved profile scored higher on the self-concept of their relationship with their parents, in language, in mathematics and their general self-concept than the group with moderate victimization. The same pattern was also observed for learning goals. The findings have significant implications for the creation of person-centred cyberbullying prevention programmes that permit a more targeted approach to cyberbullying behaviours in order to halt its progress.     

Social welfare in the light of topic modelling

With an increased focus on social well-being in response to a burgeoning global economy exposing the weaknesses of social welfare policies, research output in the field has grown exponentially. Keeping track of the evolving research themes proves difficult due to the steady rise in the number of studies published in the interdisciplinary field of social welfare. Therefore, researchers need a comprehensive overview to confirm the current shape of the field based on the published research. Using a latent Dirichlet allocation algorithm as a topic modelling technique, this study identified 12 prominent themes from more than 10,000 research outputs on social welfare published from 2000 to 2020 in Scopus-indexed journals. Such an exploratory text-mining approach to literature review provides broad insights into the diversity of research and may serve as a foundation for further in-depth studies. Identifying these 12 thematic areas and their sub-themes allows us to articulate the complexity and diversity of social welfare issues, which go far beyond the field of well-established welfare economics or social work. The study shows that the topic of ‘social welfare’ has not only evolved over time but has significantly broadened its meaning. It can no longer be solely synonymous with institutional social security. We contend that research in this area needs to take into account a broader and more systematic range of determinants constituting the dynamic character of social welfare.     

Impact of early memories and current experiences of warmth and safeness on adolescents' psychological distress

A variable-centered and a person-centered approach were performed to examine the role of early memories of warmth and safeness (EMWS) and current experiences of warmth and safeness (CEWS) on depressive and anxious symptoms among adolescents from community and residential youth care (RYC) settings. Variable-centered results revealed EMWS were only indirectly (through CEWS) associated with depressive and anxious symptoms. Person-centered outcomes allowed to identify four different profiles based on EMWS and CEWS, which differed on depressive and anxious symptoms. EMWS and CEWS seem to play an important role in psychological distress during adolescence. CEWS seem to have a protective role on RYC adolescents' psychological distress, even when EMWS were poor.