Characteristic function-based inference for GARCH models with heavy-tailed innovations

We consider estimation and goodness-of-fit tests in GARCH models with innovations following a heavy-tailed and possibly asymmetric distribution. Although the method is fairly general and applies to GARCH models with arbitrary innovation distribution, we consider as special instances the stable Paretian, the variance gamma, and the normal inverse Gaussian distribution. Exploiting the simple structure of the characteristic function of these distributions, we propose minimum distance estimation based on the empirical characteristic function of properly standardized GARCH-residuals. The finite-sample results presented facilitate comparison with existing methods, while the new procedures are also applied to real data from the financial market.     

Spatial estimation and rescaled spatial bootstrap approach for finite population

In this study, an attempt has been made to improve the sampling strategy incorporating spatial dependency at estimation stage considering usual aerial sampling scheme, such as simple random sampling, when the underlying population is finite and spatial in nature. Using the distances between spatial units, an improved method of estimation, viz. spatial estimation procedure, has been proposed for the estimation of finite population mean. Further, rescaled spatial bootstrap (RSB) methods have been proposed for approximately unbiased estimation of variance of the proposed spatial estimator (SE). The properties of the proposed SE and its corresponding RSB methods were studied empirically through simulation.     

Detecting influential observations in Watson data

A method for detecting outliers in axial data has been proposed by Best and Fisher (1986 Best, D.J., Fisher, N.I. (1986). Goodness-of-fit and discordancy tests for samples from the Watson distribution on the sphere. Aust. J. Stat. 28:13–31.[Crossref] , [Google Scholar]). For extending that work, we propose four new methods. Two of them are suitable for outlier detection and they depend on the classic geodesic distance and a modified version of this distance. The other two procedures, which are designed for influential observation detection, are based on the Kullback–Leibler and Cook’s distances. Some simulation experiments are performed to compare all considered methods. Detection and error rates are used as comparison criteria. Numerical results provide evidence in favor of the KL distance.     

Multivariate discrete reversed hazard rates

In the present paper, we define and study four versions of multivariate discrete reversed hazard rates, namely scalar reversed hazard rate, vector reversed hazard rate, alternative reversed hazard rate, and conditional reversed hazard rate. Various properties of these functions are studied. Interrelationships between these reversed hazard rates are explored. We also present characterization of discrete distributions using these reversed hazard rates.     

The importance of the size of the social network and residential proximity in the reception of informal care in the European Union

This paper explores which factors affect the reception of informal care among those dependent people aged 65 and over in Europe, starting from the so-called Behavioural Model of Health Service Use introduced by Andersen. The data employed are drawn from the fourth wave of the Survey of Health, Ageing, and Retirement. The final sample consists of a total of 17,284 older dependent people of which 4529 (26.2%) received informal care. The main novelty is the incorporation of different characteristics of the social network of the individual (presence of children, size and residential proximity) among the factors that enable the reception of informal care. In particular the two latter aspects are combined in one sole indicator of distance to the social network. In addition to ‘traditional factors’ like age or degree of dependency, all the characteristics of the social network are found to influence the likelihood of receiving informal care. This reveals the need for taking into consideration the role played by social networks when governments design care programmes, especially in the current scenario of rising demand for care.     

Geographic distance and intergenerational relationships in Chinese migrant families

ABSTRACT

This study examines the effect of adult Chinese migrants’ geographic distance from home on their intergenerational relationships with parents who remain behind. We compared monetary and family care support as well as emotional relationships among four parent-child groups: older adults and international migrant children, older adults and internal migrant children (who migrated to other cities in China), older adults and coresiding children, and older adults and local children (living in the same city as their parents). Data were derived from 332 older adults in Beijing, China, with at least one child who migrated to another country or city. Results from chi-square tests, anaylsis of variance (ANOVA) tests, and regression analyses indicate that international and internal migrant children maintain similar intergenerational relationships with their parents, and that both of those groups are less likely than coresiding and local children to have family care exchanges and emotionally close relationships with their parents. The results may help professionals develop supportive services and policies for older adults in migrant families.     

能源价格波动、诱导性技术进步与中国环境全要素生产率

随着能源的"金融属性"日益凸显,科学评估能源价格波动对经济增长和环境改善的综合影响具有重要的理论和现实意义。本文基于参数化的双曲线距离函数,将能源价格因素纳入环境全要素生产率（ETFP）的分析框架,剖析能源价格波动影响ETFP变动的内在机理;在此基础上,运用1995~2015年省际面板数据,考察能源价格诱导性技术进步对我国ETFP提升的促进作用及其时空分异规律,并识别该技术进步的具体偏向类型。研究结果表明：近20年来我国能源价格诱导性技术进步的平均速率为0.22%,其对ETFP变动的提升作用相对较弱,并表现出较强的时空分异特征。此外,从要素投入来看,能源价格诱导性技术进步总体上呈现资本和能源节约—劳动力使用型特征;从产出侧来看,其主要偏向于SO₂的减排,但对CO₂减排和GDP扩张的诱导作用不甚明显。     

东道国风险、文化距离与中国企业对外直接投资

随着中国企业对外直接投资规模的不断增长和国际影响力的不断提升,投资稳定性和区位选择中的东道国风险影响也备受关注。以此为背景研究东道国文化距离对中国企业对外直接投资风险选择的影响,在度量东道国文化距离和风险的基础上,实证研究发现:当东道国与中国文化距离较小时,东道国较高经济和政治风险能促进中国企业对外直接投资;当东道国与中国文化距离较大时,东道国较高的经济和政治风险会阻碍中国企业对外直接投资。因而,中国企业对外直接投资的风险偏好不是绝对的,而是依赖于外部东道国文化距离条件。     

Routing in a queueing system with two heterogeneous servers in speed and in quality of resolution

Heterogeneous servers, in manufacturing and service systems, may have different speeds and different quality levels for the provided service or good For a two-server queueing model, we formulate the job routing problem for minimizing the stationary weighted sum of the expected time spent in the system and the number of unsatisfied customers per time unit. Using a Markov decision process approach, we prove that the optimal routing policy of jobs to service is a threshold policy that depends on the queue length. When the number of waiting jobs in the queue is below a certain threshold, only one server should work and the other one remains idle. At or above this threshold, both servers should serve jobs. This is an extension of the known result where only the heterogeneity in speed is considered.