Filtration enlargement-based time series forecast in view of insider trading

This survey reviews filtration enlargement models in view of insider trading. Although filtration enlargement aptly models insiders' informational advantage, the theoretical results have not attracted the attention of the empiricists, owing mainly to the lack of a bridge transforming the results to testable hypotheses, and/or the absence of econometrics method linking the hypotheses and the data. This survey provides a feasible avenue to estimate insider information and to detect trading from a relatively sophisticated theoretical model, where the dynamics of publicly available data (e.g., stock price) implies insider information before the information is completely digested. We complete the survey with an empirical illustration based on simulated data.     

Towards a real-time prediction of waiting times in emergency departments: A comparative analysis of machine learning techniques

Emergency Departments (EDs) can better manage activities and resources and anticipate overcrowding through accurate estimations of waiting times. However, the complex nature of EDs imposes a challenge on waiting time prediction. In this paper, we test various machine learning techniques, using predictive analytics, applied to two large datasets from real EDs. We evaluate the predictive ability of Lasso, Random Forest, Support Vector Regression, Artificial Neural Network, and the Ensemble Method, using different error metrics and computational times. To improve the prediction accuracy, new queue-based variables, that capture the current state of the ED, are defined as additional predictors. The results show that the Ensemble Method is the most effective at predicting waiting times. In terms of both accuracy and computational efficiency, Random Forest is a reasonable trade-off. The results have significant practical implications for EDs and hospitals, suggesting that a real-time performance monitoring system that supports operational decision-making is possible.     

旅游形象认知的时间顺序对旅游目的地形象认知的影响研究--以银川沙湖与榆林红碱淖为例

旅游者对旅游目的地的形象认知是影响旅游活动的重要因素,对旅游目的地形象定位和市场营销策略的选择都具有重要的参考价值。许多因素对旅游目的地形象认知都产生影响,其中认知的时间特征对旅游目的地形象认知的影响是一个值得关注的新课题:旅游者对不同旅游目的地形象认知的先后顺序对旅游目的地形象认知是否产生影响以及这种影响的程度如何。文章以银川沙湖与榆林红碱淖为例,对旅游者对旅游目的地形象认知中的“先入为主”与“既成事实”效应进行了分析,初步证明旅游者对不同旅游目的地形象感知的先后顺序对旅游目的地形象认知产生影响,并针对案例景区的情况,强调了旅游形象定位与市场营销中的先发优势,提出了自己的观点。     

上市公司财务危机实时预警系统研究

我国加入WTO后，在给上市公司带来良好机遇的同时，也使其面临着严峻的挑战。笔者认为建立上市公司财务危机实时预警系统已势在必行。本文首先阐述了上市公司财务危机实时预警的基本前提，接着就如何架构上市公司财务危机实时预警的模式和机制作了探讨，并提出了相关的建议。     

基于JIT方式的中小企业在制品管理问题研究

在制品管理是中小企业生产过程中困扰已久的问题之一,尤其是在多工序、多品种制造业企业中。由于企业产品特征导致在制品管理的难度,JIT方式难以付诸实践。结合JIT思想与ERP系统,实现对在制品的物流与信息流有效控制,对提高生产效率、降低物流成本具有重要的意义。针对中小企业物料管理存在的问题及局限性进行分析,从而提出相关的改进建议。     

我国地方政府债务风险及其预警:问题及对策

我国地方政府财政风险有其特殊的历史背景和生成机理,而且有关预警信息取得困难,财政危机的表现模糊,这些问题给有效预警带来困难。不仅如此,现有的预警研究在预警理论和预警方法上也存在诸多问题,本文试图根据我国地方政府财政风险的特殊性以及现有预警存在的问题,提出相应的预警对策。     

对土地财政与地方经济增长相关性的探讨

近些年来,之所以演化出土地财政这一具有非褒义的概念,是因为有着深刻的社会背景。这不仅有财政体制上的原因,也有城市自身扩张与政府官员政绩考核的原因。目前,土地财政在推动地方经济增长的过程中发挥了重要作用。实证分析表明,GDP虽不是土地性财政收入的Granger因,而GDP却是土地性财政收入的Granger果。地方经济增长过度依赖于土地财政,不仅会造成严重的不良后果,如威胁我国粮食安全、不利于和谐社会建设、加剧购房居民的负担等,而且也会扩大政府的寻租空间。为此,地方政府必须寻求摆脱经济增长对于土地财政依赖的路径选择,要转变经济增长观念、推进财政体制改革、充分发挥土地流转机制的作用、不断完善土地法规的相关内容等。     

从美日经验看地方政府债券制度

地方政府债务风险已经成为威胁我国经济安全与社会稳定的巨大隐患。地方政府是制度变迁的主体,造成地方财政困境的根本原因在于地方政府事权、财权不对称,没有规范的制度化融资渠道。而只要存在中央与地方分权的财政联邦主义,就具备发行地方政府债券的前提。     

以城乡互动推进就地就近城镇化发展分析

“伪城镇化”、“半城镇化”现象的背后是中国城乡二元经济“一元化”过程中的“农民进城”与城市吸融功能不足的矛盾、“小城镇化浪潮”与农村城镇化的发展潜力不足的矛盾。结合中国国情的高质量城镇化发展模式在于守地式的就近就地城镇化发展,而守地式发展的关键在于农村产业发展,农村产业的发展又依赖于城乡市场与产业的互动。这需要发展立足农村的“产供销一体化”大型商贸企业,破解农村市场劳动力流转、土地流转、融资与技术及管理水平低下问题,构建城乡产业互动的交换利益基础,优化城乡产业体系配套和互补的对接方式,提升城乡产业合作的分工层次。     

Asymmetries and interdependencies in time use between Italian parents

In recent decades, changes in parents’ attitudes towards the importance of spending time with children to optimize their future behaviour and cognitive development have greatly affected patterns of time allocation among both working and nonworking parents in all developed countries. We compare the two waves of the Italian Time Use dataset (1988 and 2002) to analyse how family time allocation changed over time in a country that was undergoing a marked increase in female employment rate and a continuous decline in total fertility rate. We focus especially on how parents’ time with their children depends on their employment status and household characteristics. Using a simultaneous sequential approach, we consider links among the different time uses of individuals and correlations with spouses’ decisions. We find that wives’ time at work time strongly influences the time spent by both spouses with their children in 2002, but not in 1988. Fathers were much more involved in childcare and rearing in 2002 than in 1988. In general, as women's work time increased, substitutes for their childcare time were found within the household (fathers or other co-resident adults).