Exact joint forecast regions for vector autoregressive models

Assume that a k-element vector time series follows a vector autoregressive (VAR) model. Obtaining simultaneous forecasts of the k elements of the vector time series is an important problem. Based on the Bonferroni inequality, Lutkepohl (1991) derived the procedures which construct the conservative joint forecast regions for the VAR model. In this paper, we propose to use an exact method which provides shorter prediction intervals than does the Bonferroni method. Three illustrative examples are given for comparison of the various VAR forecasting procedures.     

Shared and unique characteristics of school,cyber and family victimization among school-aged children in Hong Kong

Victimizations from online and offline violence, such as sibling violence, school violence and witness of family violence, both have negative associations with victims' mental health and may share similar individual and family characteristics. This study aims to explore the common and differentiated characteristics in the prediction of school, cyber and family victimization and whether there are unique associations within these victimization types. We employed a two-stage stratified sampling method to collect a representative sample of 5567 children aged 3–17 from a cross-sectional, school-based survey in Hong Kong. Results showed that all types of child victimization, including sibling, school and cyberbullying, as well as the witness of violence at home, were positively correlated with each other. Children's age was positively related to the occurrence and cooccurrence of all types of child victimization. Frequent family residential mobility and parents' higher education level were positively related to all types of children's victimization. The scores of all aspects of children's paediatric quality of life were found negatively related to children's school victimization. This study provides insight into the unique and shared elements of children's online and offline victimization. Knowledge of the distinguished familial gradients of child victimization at home and beyond could benefit the development of child victimization prevention.     

Out of Sight,Out of Mind? Patterns of Transnational Contact Among Chinese and Indian Immigrants in Toronto1

There has been considerable discussion in recent decades about the integration patterns of new immigrants. Recognizing advancements in technology and the increased economic integration of countries, some researchers have suggested that the emerging integration trend for immigrants is the transnational pattern, whereby immigrants maintain contact with the home countries. To advance the discussion, this study focuses on general transnational contact, a basic form of transnational activity. The study draws from recently collected large‐scale survey data to explore the patterns of transnational contact within two recent immigrant groups, Asian Indians and Chinese, in Toronto. Our findings show that only a small percentage of immigrants maintain intensive and extensive transnational contact. As well, our findings are less consistent with the transnational perspective than with the assimilation perspective on the effects of socioeconomic background on transnational contacts.     

Using Neural Networks to Model the Behavior and Decisions of Gamblers,in Particular,Cyber-Gamblers

This article describes the use of neural networks (a type of artificial intelligence) and an empirical data sample of, inter alia, the amounts of bets laid and the winnings/losses made in successive games by a number of cyber-gamblers to longitudinally model gamblers’ behavior and decisions as to such bet amounts and the temporal trajectory of winnings/losses. The data was collected by videoing Texas Holdem gamblers at a cyber-gambling website. Six “persistent” gamblers were identified, totaling 675 games. The neural networks on average were able to predict bet amounts and cumulative winnings/losses in successive games accurately to three decimal places of the dollar. A more important conclusion is that the influence of a gambler’s skills, strategies, and personality on his/her successive bet amounts and cumulative winnings/losses is almost totally reflected by the pattern(s) of his/her winnings/losses in the few initial games and his/her gambling account balance. This partially invalidates gamblers’ illusions and fallacies that they can outperform others or even bankers. For government policy-makers, gambling industry operators, economists, sociologists, psychiatrists, and psychologists, this article provides models for gamblers’ behavior and decisions. It also explores and exemplifies the usefulness of neural networks and artificial intelligence at large in the research on gambling.     

农业综合生产自组织功能优化探讨——基于耗散结构理论视角

农业综合生产系统具备耗散结构的基本条件,拥有自组织功能。城市化和工业化进程一定程度上削弱了它的自组织功能,应从系统负熵流的增加、非平衡性的加强、非线性特征的强化和巨涨落的催生等入手,优化农业综合生产的自组织功能。     

浅谈金融危机中加强社会主义核心价值体系建设

由美国次贷危机引发的全球性金融危机是一场经济危机、深度的思想道德危机和社会危机,对我国经济社会发展造成不小的冲击和影响,但同时,又是加强社会主义核心价值体系建设的有利时机。我们要抓住这一战略机遇,通过大众化、生活化、主流化、形象化和制度化的道路,使社会主义核心价值体系基本内容要求转化为我国人民的自觉追求,为应对国际金融危机和建设和谐社会构建强大的共同思想道德基础。     

基于SYS-GMM的中国人口结构变化与经济增长关系研究

本文利用中国29个省份20年的面板数据,探讨了人口结构变化对储蓄、投资和经济增长的影响。我们将人口结构指标引入传统的经济增长模型中,并用固定效应模型和SYS-GMM计量方法分别测算其对储蓄、投资和经济增长的效应。考虑到老年抚养比在经济增长方程的内生性,我们还将滞后30年的就业人数比率作为工具变量来识别老年抚养比对经济增长的因果效应。结果显示老年抚养率对储蓄、投资和经济增长存在显著的正相关。人口增长率对储蓄和投资有着负相关,但对经济增长没有影响。工作年龄人口比率对储蓄率存在负相关,对投资和经济增长存在正向影响但估计的回归系数不显著。在加入其它制度和人口变量之后回归结果依然稳定。     

A study of R2 measure under the accelerated failure time models

For right-censored data, the accelerated failure time (AFT) model is an alternative to the commonly used proportional hazards regression model. It is a linear model for the (log-transformed) outcome of interest, and is particularly useful for censored outcomes that are not time-to-event, such as laboratory measurements. We provide a general and easily computable definition of the R² measure of explained variation under the AFT model for right-censored data. We study its behavior under different censoring scenarios and under different error distributions; in particular, we also study its robustness when the parametric error distribution is misspecified. Based on Monte Carlo investigation results, we recommend the log-normal distribution as a robust error distribution to be used in practice for the parametric AFT model, when the R² measure is of interest. We apply our methodology to an alcohol consumption during pregnancy data set from Ukraine.     

Mildly explosive autoregression with mixing innovations

In this paper, the limit distribution of the least squares estimator for mildly explosive autoregressive models with strong mixing innovations is established, which is shown to be Cauchy as in the iid case. The result is applied to identify the onset and the end of an explosive period of an econometric time series. Simulations and data analysis are also conducted to demonstrate the usefulness of the result.     

Hong Kong: workfare in the world's freest economy

Chan CK. Hong Kong: workfare in the world's freest economy Int J Soc Welfare 2011: 20: 22–32 © 2009 The Author(s), Journal compilation © 2009 Blackwell Publishing Ltd and the International Journal of Social Welfare. Workfare was introduced in many countries to suppress welfare dependency and reduce social security expenditures. However, workfare was launched in Hong Kong when there was only a relatively small social security budget and its citizens still strongly adhered to the ideologies of self‐reliance. It was found that workfare has performed several functions in Hong Kong. First, by forcing unemployed claimants to give up benefits, Hong Kong has been able to save on social security expenditures. Second, workfare has combined with Hong Kong's semi‐democratic polity so that extremely stigmatising welfare measures have been implemented. Third, it has pushed poor citizens into the labour market without having any protection over wages and working hours. Thus, the combination of workfare and a semi‐democratic polity has successfully suppressed Hong Kong's welfare demands and strengthened its self‐help spirit. As a result, Hong Kong's minimal social security scheme and its low tax policy have been maintained.