Unified multivariate survival model with a surviving fraction: an application to a Brazilian customer churn data

In this paper we propose a new lifetime model for multivariate survival data in presence of surviving fractions and examine some of its properties. Its genesis is based on situations in which there are m types of unobservable competing causes, where each cause is related to a time of occurrence of an event of interest. Our model is a multivariate extension of the univariate survival cure rate model proposed by Rodrigues et al. [37 J. Rodrigues, V.G. Cancho, M. de Castro, and F. Louzada-Neto, On the unification of long-term survival models, Statist. Probab. Lett. 79 (2009), pp. 753–759. doi: 10.1016/j.spl.2008.10.029[Crossref], [Web of Science ®] , [Google Scholar]]. The inferential approach exploits the maximum likelihood tools. We perform a simulation study in order to verify the asymptotic properties of the maximum likelihood estimators. The simulation study also focus on size and power of the likelihood ratio test. The methodology is illustrated on a real data set on customer churn data.     

A Proportional Hazards Regression Model for the Subdistribution with Covariates‐adjusted Censoring Weight for Competing Risks Data

With competing risks data, one often needs to assess the treatment and covariate effects on the cumulative incidence function. Fine and Gray proposed a proportional hazards regression model for the subdistribution of a competing risk with the assumption that the censoring distribution and the covariates are independent. Covariate‐dependent censoring sometimes occurs in medical studies. In this paper, we study the proportional hazards regression model for the subdistribution of a competing risk with proper adjustments for covariate‐dependent censoring. We consider a covariate‐adjusted weight function by fitting the Cox model for the censoring distribution and using the predictive probability for each individual. Our simulation study shows that the covariate‐adjusted weight estimator is basically unbiased when the censoring time depends on the covariates, and the covariate‐adjusted weight approach works well for the variance estimator as well. We illustrate our methods with bone marrow transplant data from the Center for International Blood and Marrow Transplant Research. Here, cancer relapse and death in complete remission are two competing risks.     

网络突发事件的生成与治理： 基于风险的社会放大框架的分析

从风险的角度看,网络突发事件就是一个以网络为主要传播媒介的风险的社会放大过程,也是一个在网络与社会现实不断互动中放大社会风险的系统.本文以风险的社会放大框架为分析工具,对网络突发事件的酝酿与生成机制进行深入的分析,并在此基础上,提出了要以风险治理为切入点对网络突发事件进行治理,从风险控制转向风险沟通,重构风险传播中政府、媒体和公众三者关系等若干政策性建议.     

论动因竞争对语序自由度的影响——以Hawkins长度顺序和可移动原则为例

流行于语言学教科书中的一个观点是:语序的自由度跟形态丰富程度成正比。这种观点有很大的局限。引入类型学“动因竞争”这个概念来讨论Hawkins提出的影响名词短语修饰语语序的“可移动原则”和“长度顺序原则”,可以得出结论:语序动因的运用程度是影响语序自由度的重要因素,只是该因素长期被忽视了,而“语序动因运用规律”则可说明此问题。     

中国商业银行的现状分析

国有商业银行是我国金融体系的主体,但由于长期受计划经济的影响,国有商业银行远远不能适应市场经济,特别是金融全球化发展趋势的需要。作者针对我国四大国有商业银行在机构设置、业务经营、管理手段以及金融创新等方面存在的问题,提出收缩管理半径,减员增效;实行本币与外币业务经营及管理一体化;强化商业银行市场营销;提高金融电子化水平,开展和完善网上银行业务;加强国有商业银行内部风险控制等有效对策,完善网上银行的运行机制,加强国有商业银行的竞争力。     

Internet risks and expert views: a case study of the insider perspectives of youth workers in Hong Kong

This study collects and analyses the viewpoints of front-line youth workers regarding the notion of ‘Internet risks’. Previous studies have examined and discussed various dangers of the Internet. Parental, school, and governmental interventions are often called for by those concerned. The implicit assumption is that these are the people who possess the expertise to tackle the problems at hand. Through participation in three forums focusing on ‘Internet risks’, and in-depth interviews with 10 such ‘experts’ in Hong Kong, the study examines if this is a valid assumption. It finds that experts perceive Internet risks rather differently. In addition to the more conventional views about content, contact and conduct risks, our interviewees are aware that a new order is quickly emerging in the new media environment. Despite being considered as ‘experts’, they do not necessarily know how to tackle the so-called ‘youth-at-risk’. Rather, they are exploring how they would capitalize on the opportunities offered by the developments. The key findings highlight the need to critically review the notion of ‘Internet risks’. As with other risk frameworks, the ultimate aim is to develop intervention programmes. In this regard, risks are often treated as concrete problems that can be solved. Youth experts, however, find that the changing scope, speed and persistence of communication in today's information society present the biggest challenge in youth work. The existing framework of risks was unable to describe and account for such risks. In response, Internet risk has to be reconceptualized so that more updated, relevant and imaginative intervention can be introduced.     

转型时期中国电视剧的投融资风险

我国电视剧行政管理体制一直沿袭着与计划经济相应的管理方式。20世纪80年代以来电视剧生产开始转型。这种变化,实际上是投融资渠道发生微妙变化的结果。电视剧投融资渠道的扩展,促进了电视剧生产制作的繁荣,但繁荣的表面无法遮蔽无处不在的政策风险、市场风险与信用风险。这三种风险成为制约中国电视剧发展的“瓶颈”。电视剧投融资机制如何不断探索适应市场的生存方式,进行自身转型,成为新世纪的难题。     

我国财政赤字和货币供应量联动性的实证模型分析

近期以来国际金融危机的加深,进一步揭示了一国财政赤字与宏观经济之间的深刻关联。进入新世纪以来,我国运用财政赤字的手段和方法不断改进,对于我们应对国际金融市场的动荡、促进内需和经济增长起到了很大作用。但同时,财政赤字与货币发行量之间不可调和的正向关系,也给我国经济体系带来了一定的隐患。因此,通过理论梳理与实证分析来理清赤字规模和货币供应量之间的关系,有助于我们今后宏观经济管理手段和金融市场监管能力的提升。     

我国企业海外撤资的实物期权分析

由于世界经济形势变化、地区政局不稳和企业对国际市场的误判,我国部分对外投资企业亏损严重,面临着从海外撤资的决择。利用实物期权法分析企业退出问题,参照贝尔曼方程,构建撤资决策的实物期权模型,分析对外投资企业撤资决策的价值。算例分析表明,对外投资企业选择的贴现率、利润的波动率和撤资成本的变化均能影响撤资的时机和方式。我国对外投资企业应根据形势变化和自身实力,不断加强自身抵抗风险的能力,灵活选择趁机抢占国外市场的进攻策略,或尽早撤出以获得放弃期权价值的防守策略。